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Danfoss BC283429059843 Gas Detecting Sensors
Specifications
- Product: Danfoss Gas Detection Modbus communication
- Communication Interface: Modbus RTU
- Controller Address: Slave ID default = 1 (can be changed)
- Baud Rate: 19,200 baud
- Data Format: 1 start bit, 8 data bits, 1 stop bit, even parity
Product Usage Instructions
Part 1 – Modbus communication from the Danfoss Gas Detection Controller
Serial Modbus Interface at the X BUS
- Please note: Standard Modbus Protocol does not include the dedicated gas detection SIL safety communication Protocol. Safety aspect of SIL1/SIL2 is not related to this bus interface.
- This functionality is available from display version 1.00.06 or higher.
Definition of Communication:
- The gas controller operates a the interface X bus only as MODBUS slave.
- Controller Address = Slave ID default = 1 (can be changed in Display Parameters).
Baud Rate Configuration:
- Baud rate: 19,200 baud (not changeable)
- Data Format: 1 start bit, 8 data bits, 1 stop bit, even parity
Modbus Function 03 – Read Holding Registers
This function is used to receive data from the Danfoss gas detection controller. There are 9 data blocks available:
- Current value of digital sensors addresses 1 to 96d.
- Current value of analog sensors addresses 1 to 32d.
- Average value of digital sensors.
- Average value of analog sensors.
- Measuring range of digital sensors.
- Measuring range of analog sensors.
Representation of Measured Values:
The measured values are shown in Integer format with specific factors based on the measuring range.
FAQ
- Q: Can the Controller Address (Slave ID) be changed?
A: Yes, the Controller Address can be changed in Display Parameters. - Q: What is the Baud Rate configuration for the gas controller X bus?
A: The Baud Rate is fixed at 19,200 baud and cannot be changed. - Q: How are the measured values represented?
A: The measured values are represented in Integer format with factors based on the measuring range as detailed in the manual.
User Guide
Danfoss Gas Detection Modbus communication
Part 1 – Modbus communication from the Danfoss Gas Detection Controller
Serial Modbus Interface at the X BUS
- Please note:
- Using standard Modbus Protocol will not include the dedicated gas detection SIL safety communication Protocol.
- Safety aspect of SIL1/SIL2 is therefore not related to this kind of bus interface.
- This functionality is available from display version 1.00.06 or higher.
- The standard protocol for an additional serial port of the gas controller X bus is ModBus RTU.
- Definition of communication
- The gas controller operates at the interface X bus only as MODBUS slave.
- Controller Address = Slave ID default = 1, (can be changed in Display Parameters).
- Baud rate 19,200 baud (not changeable)
- 1 start bit, 8 data bits
- 1 stop bit, even parity
- Address = Start address see descriptions below Length = Number of Datawords see descriptions below.
Modbus Function 03
Read Holding Registers (reading of holding registers) are used to receive data from the Danfoss gas detection controller. There are 9 data blocks
- Current value of digital sensors
- Current value of digital sensors – sensor addresses 1 to 96d.
- Current value of digital sensors – sensor addresses 1 to 96d.
- Current value of analog sensors
- Current value of analog sensors – sensor addresses 1 to 32d.
- Available in MODBUS Start address.. 2001d to 2032d.
Representation of measured values: The measured values are shown in the Integer format with a factor of 1, 10, 100 or 1000. The factor depends on the respective measuring range and is used as follows:
| Range | Factor |
| 1 -9 | 1000 |
| 10-99 | 100 |
| 100-999 | 10 |
| From 1000 on | 1 |
If the value is below -16385, it is an error message and should be considered as a hexadecimal value in order to break the errors down.
- Average value of digital sensors
Average value of digital sensors – sensor addr.. 1 to 96d. Available in MODBUS Start address.. 3001d to 3096d. - Average value of analog sensors
Average value of analog sensors- sensor addr.. 1 to 32d. Available in MODBUS Start address.. 4001d to 4032d.
- Measuring range of digital sensors
- Measuring range of digital sensors – sensor addr. 1 to 96d. Available in MODBUS Start address.. 5001d to 5096d.
- Measuring range of analog sensors
- Measuring range of analog sensors – sensor addr.. 1 to 32d. Available in MODBUS Start address.. 6001d to 6032d
- Display of the alarms and the respective latching bits of digital sensors
- Display of the local alarms generated by the gas detection controller as well as of the respective latching bits of digital sensors – sensor addresses 1 to 96d. Available in MODBUS Start address 1201d to 1296d
- Display of the alarms and the respective latching bits of analog sensors
- Display of the local alarms generated by the gas detection controller as well as of the respective latching bits of analog sensors – sensor addresses 1 to 32d. Available in MODBUS Start address 2201d to 2232d
Here, the representation in the hexadecimal form is easier to read because the data are transmitted in the following form:
0xFFFF =
| 0x | F | F | F | F |
| 0b | 1111 | 1111 | 1111 | 1111 |
| Local latching | Controller latching | Local alarms | Controller alarms |
- There are four status bits for the four alarm stages each.
- 1 = alarm or latching active
- 0 = alarm or latching not active
- The above example:
- There are two local alarms at DP1, with the second being in latching mode.
- The first alarm generated by the gas detection controller is present at DP4.
- The first alarm generated by the gas detection controller is present at AP5.
- Relay status of the signal relays
- Relay status of the signal relays – signal relay address 1 to 96d. Available in MODBUS Start address…. 7001d to 7096d
- Relay status of the alarm relays
- Relay status of the alarm relays– alarm relay address 1 to 32d. Available in MODBUS Start address…. 8001d to 8032d
The relay status of the controller‘s fault message relay is in register 8000d.
- Gas detection controller Watch Outputs (WI), MODBUS addresses 50 to 57
- In register 50d, all watch outputs are shown as a byte as used for evaluation in the gas detection controller.
- In the Start address 51d – 57d the individual bit values are available as Integer values.
- 0d = No output set
- 1d = Switch on by clock
- 256d or 0x0100h = Switch on by Modbus 257d or 0x0101h = Switch on by Modbus and clock
Data block: Output
Start address 0d: My own slave MODBUS address at the X Bus
- Address 1d: Relay information bits of the first module (Controller Module)
- Relay 1 is bit 0 to relay 4 is bit 3
- Address 2d: Relay information bits of the extension module address_1
- Relay 5 is bit 0 to relay 8 is bit 3
- Address 3d: Relay information bits of the extension module address_2
- Relay 9 is bit 0 to relay 12 is bit 3
- Address 4d: Relay information bits of the extension module address 3
- Relay 13 is bit 0 to relay 16 is bit 3
- Address 5d: Relay information bits of the extension module address_4
- Relay 17 is bit 0 to relay 20 is bit 3
- Address 6d: Relay information bits of the extension module address_5
- Relay 21 is bit 0 to relay 24 is bit 3
- Address 7d: Relay information bits of the extension module address_6
- Relay 25 is bit 0 to relay 28 is bit 3
- Address 8d: Relay information bits of the extension module address_7
- Relay 29 is bit 0 to relay 32 is bit 3
- The addresses 9d to 24d stand for hardware analog output 1 to analog output 16.
- The definition of the values is done between 0 and 10000d ( 0 = 4mA Output; 10.000d = 20mA
- Output= full scale value of the sensor, 65535 mark as not used)..
- Status information as summary per measuring point
- The thresholds are only available on devices with
- Software Version 1.01.07 or 1.02.07 onwards.
- The starting registers of the three blocks for the digital measurement points are 1301d, 2301d, 3301d with a total length of 512 registers per block.
- The starting register of the analog measuring points is 7101d with the total length of 512 registers.
- There are 16 registers reserved per measuring point. The description of the registers is shown in the picture on the right.
- Operating data, summarized per measuring point
- The operating data are only available on devices
- Software Version 1.01.07 or 1.02.07 onwards.
- The starting registers of the three blocks for the digital measurement points are 4101d, 5101d, 6101d with a total length of 576 registers per block.
- The starting register of the analog measuring points is 8101d with the total length of 576 registers
- There are 18 registers reserved per measuring point. The description of the registers is shown in the picture on the right
Modbus-Function 05
Write Single Coil (writing of single states ON/OFF) is used to acknowledge the latching mode or the horns as well as to set clock outputs individually.
- Acknowledgement of latching mode
- For this purpose, the command 05 is sent to the address of the gas detection controller with the indication of the respective register from 1.7 or 1.8 Display of the alarms and the respective latching bits
- The acknowledgment only takes place when the value ON(0xFF00) has been sent.
- Acknowledgement of horn
- For this purpose, command 05 is sent to the address of gas detection controller and register 7000d
- The acknowledgment only takes place when the value ON(0xFF00) has been sent.
- Activation of the single Watch Output via Modbus
- For this purpose, the command 05 is sent to the address of the g as detection controller with the indication of the respective register from 1.11 Display of the Watch Outputs witch register 50 not being allowed
Modbus Function 06
- Write Single Registers (writing of single registers) is used to write on individual registers in the gas detection controller.
- Currently, it is only possible to write on the own slave address.
- Modbus address 0 (see 1.12)
Modbus-Function 15
Write Multiple Coil (writing multiple states OFF ON) is used to set all watch outputs at once. The command must be sent to gas detection controller address with the indication of register 50d with a maximum length of 7 bits.
Modbus Function 16
- Write Multiple Registers (writing of several registers) is used to write on several registers in the gas detection controller. Currently, it is only possible to write on the own slave address. Modbus address 0 (see 1.12)
- All other parameter changes are not permitted for safety reasons; therefore, the data direction is clearly defined from the warning system to the open MODBUS side. Retroaction is not possible.
Serial Modbus Interface at the ModBUS
- The standard protocol for an additional serial port of the gas controller Modbus is ModBus RTU.
- Definition of communication:
- The gas detection unit (Basic, Premium or Heavy Duty) operates at the RS 485 interface (Bus A, Bus
- B Terminals) only as MODBUS slave.
- Parameter for communication:
- Baud rate 19,200 baud
- 1 start bit, 8 data bits
- 1 stop bit, even parity
Fig 1: Settings for Modbus query
Modbus Function 03
Read Holding Registers (reading of holding registers) are used to receive data from the Gas Detection Controller system
- Measured Value Query (compressed form) from version 1.0
- It is possible to query the initial address 0 with a length of exactly 10 information (words).
- Example here SlaveID = Slave address = 3
Fig 1.1a: Query values
Basic and Premium units:
In the ModBus query, the values are as follows
| offs | Register Addresses 0 – 9 |
| 0 | Current Value Sensor 1 |
| 1 | Average Sensor 1 |
| 2 | Current Value Sensor 2 |
| 3 | Average Sensor 2 |
| 4 | Current Value Sensor 3 |
| 5 | Average Sensor 3 |
| 6 | Type + Range Sensor 1 |
| 7 | Type + Range Sensor 2 |
| 8 | Type + Range Sensor 3 |
| 9 | Current Temperature °C |
Fig. 1.1c: Window section from Modbus query
- Heavy Duty units:
- In the case of the Heavy Duty ModBus query, only the values of the first input are occupied, all others are shown with 0:
- Dynamic resolution for the gas information is used, that means that
- if the measuring range < 10, then the gas value is multiplied with 1000,
- if the measuring range < 100 & >=10, then the gas value is multiplied with 100, if the measuring range < 1000 & >=100, then the gas value is multiplied with 10, if the measuring range >= 1000, then
- the gas value is multiplied with 1.
- So in all cases a resolution of 1000 can be guaranteed.
Measured Values & Status Query (uncompressed form)
- Two query options are available here:
- A: Query all information via the base address of the device:
- Fixed register (start) address 40d (28h) with variable length 1 to 48 d information (words) Example here Slave ID = Slave Address = 3
- (The other addresses 4 and 5 are not necessary because all information is transferred in a block)
- B: Only query the corresponding sensor via the different individual addresses:
- The start addresses are defined according to Table 1.2c, with a fixed length of 12 value
Fig.1.2a: Modbus query parameters for version A 
Fig. 1.2b: Sensor 1 – 3 Modbus query parameters for version B
The data are arranged in the following order:
| offs | Sensor 1 | Sensor 2 | Sensor 3 |
| Device Base Address Register Addr. 40-51 | Device Base Address Register Addr. 52-63 | Device Base Address Register Addr. 64-75 | |
| Device Base Address Register Addr. 40-51 | Device Base Address +1 Register Addr. 40-51 | Device Base Address +2 Register Addr. 40-51 | |
| 0 | gastype_1 | gastype_2 | gastype_3 |
| 1 | range_1 | range_2 | range_3 |
| 2 | divisor_1 | divisor_2 | divisor_3 |
| 3 | current_value_1 | current_value _2 | current_value _3 |
| 4 | average_value_1 | average_value _2 | average_value _3 |
| 5 | error_1 | error_2 | error_3 |
| 6 | alarm_1 | alarm_2 | alarm_3 |
| 7 | di+relay | di+relay | di+relay |
| 8 | threshold_1a | threshold_2a | threshold_3a |
| 9 | threshold_1b | threshold_2b | threshold_3b |
| 10 | threshold_1c | threshold_2c | threshold_3c |
| 11 | threshold_1d | threshold_2d | threshold_3d |
Table 1.2c: Arrangement of information
Measured Values & Status Query (uncompressed form)
| Offs | Sensor 1 | Values | Sensor 2 | Values | Sensor 3 | Values |
| Sensor 1 Register addr 40-51 | Sensor 2 Register addr 52-63 | Sensor 3 Register addr. 64-75 | ||||
| Sensor 1 Register addr. 40-51 | Sensor 2 Register addr. 52-63 | Sensor 3 Register addr. 64-75 | ||||
| 0 | gastype_1 | 1302 | gastype_2 | 1177 | gastype_3 | 1277 |
| 1 | range_1 | 25 | range_2 | 100 | range_3 | 2500 |
| 2 | divisor_1 | 100 | divisor_2 | 10 | divisor_3 | 0 |
| 3 | current_value_1 | 314 | current_value_2 | 306 | current_value_3 | 1331 |
| 4 | average_value_1 | 314 | average_value_2 | 306 | average_value_3 | 1331 |
| 5 | error_1 | 0 | error_2 | 0 | error_3 | 0 |
| 6 | alarm_1 | 0 | alarm_2 | 0 | alarm_3 | 112 |
| 7 | di+relay | 12 | di+relay | 12 | di+relay | 12 |
| 8 | threshold_1a | 1301 | threshold_2a | 501 | threshold_3a | 2400 |
| 9 | threshold_1b | 1402 | threshold_2b | 602 | threshold_3b | 3600 |
| 10 | threshold_1c | 1503 | threshold_2c | 703 | threshold_3c | 1600 |
| 11 | threshold_1d | 1604 | threshold_2d | 803 | threshold_3d | 80 |
Table 1.2e: Value example
Register description of measuring values for 1.2 A and 1.2 B
| Addresses | offs | Picture Name | Meaning |
| 40,52,64 | 0 | Gastype_x ui16 | Gas type code of sensor 1, 2, 3 see table |
| 41,53,65 | 1 | Range_x ui16 | Measuring range of sensor 1, 2, 3 (integer without translation) |
| 42,54,66 | 2 | divisor_x ui16 | Divisor factor of sensor 1, 2, 3 (e.g. register value = 10 -> all measured values and alarm thresholds have to be divided by 10. |
| 43,55,67 | 3 | cur_val_x signed i16 | Current value of sensor 1, 2, 3: Value presentation as integer (is multiplied with the divisor factor, therefore the actual gas value has to be divided by the divisor factor) |
| 44,56,68 | 4 | average_val_x signed i16 | “Average value of sensor 1, 2, 3: Value presentation as integer (is multiplied with the divisor factor, therefore the actual gas value has to be divided by the divisor factor)” |
| 45,57,69 | 5 | error_x ui16 | Error information, binary coded, see table |
| 46,58,70 | 6 | alarm_x ui16 | Alarm status bits of sensor 1, 2, 3, binary coded, see table |
| 47,59,71 | 7 | di+rel_x uii16 | Alarm status bits of relay 1 – 5, and digital input states 1-2 binary coded, see table |
| 48,60,72 | 8 | threshold_x y ui16 | Threshold 1 of sensor 1, 2, 3, Value presentation as integer (is multiplied with the divisor factor, therefore the actual gas value has to be divided by the divisor factor) |
| 49,61,73 | 9 | threshold_x y ui16 | Threshold 2 of sensor 1, 2, 3, Value presentation as integer (is multiplied with the divisor factor, therefore the actual gas value has to be divided by the divisor factor) |
| 50,62,74 | 10 | threshold_x y ui16 | Threshold3 of sensor 1, 2, 3, Value presentation as integer (is multiplied with the divisor factor, therefore the actual gas value has to be divided by the divisor factor) |
| 51,63,75 | 11 | threshold_x y ui16 | Threshold 4 of sensor 1, 2, 3, Value presentation as integer (is multiplied with the divisor factor, therefore the actual gas value has to be divided by the divisor factor) |
Table 1.2f: Register description of measuring values for 1.2 A and 1.2 B
Operating data
- Two query options are available here:
- A: Query all information via the base address of the device:
- Fixed register (start) address 200d (28h) with length 1 to 48 d information (words)
- Example here: Slave ID = Slave Address = 3
- (The other addresses 4 and 5 are not used here.) Start Address always 200d.
- Number of sensors: 1 2
- Lengths: 18 36
- B: Only query the corresponding sensor via the different individual addresses:
- The start addresses are defined according to Table 1.2c, with a fixed length of 18 values
Fig.1.3a: Modbus query parameters Version A 
Fig. 1.3b: Sensor 1 – 3 Modbus operating data Modbus query parameters Version B 
Arrangement of the data
| offs | Sensor 1 (all devices) | Sensor 2 (Only Premium) |
| Device base address Start address 200-217d | Device base address Start address 218-235d | |
| Device base address Start address 200-217d | Device base address +1 Start address 200-217d | |
| 0 | prod_dd_mm_1 | prod_dd_mm_1 |
| 1 | prod_year_1 | prod_year_2 |
| 2 | serialnr_1 | serialnr_2 |
| 3 | unit_type_1 | unit_type_2 |
| 4 | operating_days_1 | operating_days_2 |
| 5 | days_till_calib_1 | days_till_calib_2 |
| 6 | opday_last_calib_1 | opday_last_calib_2 |
| 7 | calib_interv_1 | calib_interv_2 |
| 8 | days_last_calib_1 | days_last_calib_2 |
| 9 | sensibility_1 | sensibility_2 |
| 10 | cal_nr_1 | cal_nr_2 |
| 11 | tool_type_1 | tool_type_2 |
| 12 | tool_nr_1 | tool_nr_2 |
| 13 | gas_conz_1 | gas_conz_2 |
| 14 | max_gas_val_1 | max_gas_val_2 |
| 15 | temp_min_1 | temp_min_2 |
| 16 | temp_max_1 | temp_max_2 |
| 17 | free | free |
Table 1.3c: Arrangement of the data
Register description of operating data acc. to 1.3 A and 1.3 B
| Adresses | offset | bildname | Meaning |
| 200,218,236 | 0 | prod_dd_mm ui16 | = Device manufacturing day + month, hex coded e.g. 14.3: 0x0E03h = 14 (day) 3 (month)(year) |
| 201,219,237 | 1 | prod_year ui16 | Device manufacturing year e.g. 0x07E2h = 2018d |
| 202,220,238 | 2 | Serialnr ui16 | Manufacturer’s device serial number |
| 203,221,239 | 3 | unit_type ui16 | Device type: 1 = Sensor Head 2 = Basic, Premium unit 3 = Gas Detection Controller |
| 204,222,240 | 4 | operating_days ui16 | Number of current operating days |
| 205,223,241 | 5 | days_till_calib signed i16 | Number of remaining operating days until next maintenance – negative values stand for exceeded maintenance time limit |
| 206,224,242 | 6 | opday_last_calib ui16 | Operating days until last calibration |
| 207,225,243 | 7 | calib_interv ui16 | Maintenance interval in days |
| 208,226,244 | 8 | days_last_calib ui16 | Number of remaining operating days of the previous maintenance period until next maintenance |
| 209,227,245 | 9 | Sensibility ui16 | Current sensor sensitivity in % (100% = new sensor) |
| 210,228,246 | 10 | cal_nr b ui16 | Number of already performed calibrations |
| 211,229,247 | 11 | tool_type ui16 | Manufacturer’s serial number of calibration tool |
| 212,230,248 | 12 | tool_nr ui16 | Manufacturer’s ID number of calibration tool |
| 213,231,249 | 13 | gas_conz ui16 | Average value of the gas concentration measured at the sensor over the time |
| 214,232,250 | 14 | max_gas_val signed i16 | Highest gas concentration measured on the sensor |
| 215,233,251 | 15 | temp_min signed i16 | Lowest gas concentration measured on the sensor |
| 216,234,252 | 16 | temp_max signed i16 | Highest temperature measured on the sensor |
| 217,235,253 | 17 | ui16 | Not used |
T able 1.3d: Register description of operating data acc. to 1.3 A and 1.3 B
Gas types and units
| Gas Code | Type | Gas Type | Formula | Unit |
| 1286 | E-1125 | Ammonia | NH3 | ppm |
| 1268 | EXT | TempC | TempC | C |
| 1269 | EXT | TempF | TempF | F |
| 1270 | EXT | Humidity | Hum. | %rH |
| 1271 | EXT | Pressure | Press | mbar |
| 1272 | EXT | TOX | TOX | ppm |
| 1273 | EXT | Comb. | Comb | %LEL |
| 1275 | EXT | External | % | |
| 1276 | EXT | Digital | % | |
| 1179 | P-3408 | Ammonia | NH3 | % LEL |
| 1177 | P-3480 | Propane | C3H8 | % LEL |
| 1266 | S164 | Carbon dioxide | CO2 | % Vol |
| 1227 | S-2077-01 | R134a | C2H2F4 | ppm |
| 1227 | S-2077-02 | R407a | ppm | |
| 1227 | S-2077-03 | R416a | ppm | |
| 1227 | S-2077-04 | R417a | ppm | |
| 1227 | S-2077-05 | R422A | ppm | |
| 1227 | S-2077-06 | R422d | ppm | |
| 1227 | S-2077-07 | R427A | ppm | |
| 1227 | S-2077-08 | R437A | ppm | |
| 1227 | S-2077-09 | R438A | ppm | |
| 1227 | S-2077-10 | R449A | ppm | |
| 1227 | S-2077-11 | R407f | ppm | |
| 1230 | S-2080-01 | R125 | C2HF5 | ppm |
| 1230 | S-2080-02 | R32 | CH2F2 | ppm |
| 1230 | S-2080-03 | R404a | ppm | |
| 1230 | S-2080-04 | R407c | ppm | |
| 1230 | S-2080-05 | R410a | ppm | |
| 1230 | S-2080-06 | R434A | ppm | |
| 1230 | S-2080-07 | R507A | ppm | |
| 1230 | S-2080-08 | R448A | ppm | |
| 1233 | S-2125 | R717 | NH3 | ppm |
Table 1.3e: Table of gas types and units
Error codes occurring in the Modbus query are the same as documented in the user guide “Controller unit and Expansion module”. They are bit coded and may occur combined.
| „DP 0X Sensor Element“ | 0x8001h (32769d) Sensor element in the sensor head – error |
| „DP 0X ADC Error“ | 0x8002h (32770d) Monitoring of the amplifier and AD converter – error |
| „DP 0X Voltage“ | 0x8004h (32772d) Monitoring of the sensor and/or process power supply – error |
| „DP 0X CPU Error“ | 0x8008h (32776d) Monitoring of the processor function –error |
| „DP 0x EE Error“ | 0x8010h (32784d) Monitoring of the data storage – reports an error. |
| „DP 0X I/O Error “ | 0x8020h (32800d) Power ON / monitoring of the in/outputs of processor – error |
| „DP 0X Overtemp.“ | 0x8040h (32832d) Ambien temperature too high |
| „DP 0X Overrange“ | 0x8200h (33280d) Signal of sensor element at the sensor head is over range. |
| „DP 0X Underrange“ | 0x8100h (33024d) Signal of sensor element at the sensor head is under range. |
| „SB 0X Error“ | 0x9000h (36864d) Communication error from central unit to SB 0X |
| „DP 0X Error“ | 0xB000h (45056d) Communication error of SB to DP 0X sensor |
| „EP_06 0X Error“ | 0x9000h (36864d) Communication error to EP_06 0X module |
| „Maintenance“ | 0x0080h System maintenance is due. |
| „USV Error“ | 0x8001h (32769d) USV doesn’t work properly, can only be signalled by the GC. |
| „Power Failure“ | 0x8004h (32772d) can only be signalled by the GC. |
| „Horn Error“ | 0xA000h (40960d) can only be signalled by the GC/EP with hardware option. |
| „Warning Sign Error“ | 0x9000h (36864d) can only be signalled by the GC/EP with hardware option. |
| „XXX FC: 0xXXXX“ | Occurs, if there are several errors from one measuring point. |
Modbus Function 06
- Write Single Registers (writing of single registers) is used to write on individual registers in the gas detection controller.
- Currently, it is NOT possible to write any information.
Modbus Function 16
- Write Multiple Registers (writing of several registers) is used to write on several registers in the gas detection controller.
- This command is used to change the device addresses.
- Attention:
- They must be known in advance, and only one device with the same address may be on the bus, otherwise all devices will be readdressed.
- This example changes device address 3 to address 12
- Fixed start address 333d (0x14dh) with exact length 1 (1 word).
- After writing this command, the device can only be reached with the new address!
- All other parameter changes are not allowed for security reasons; therefore the data direction is clearly defined from the warning system side to the open MODBUS side. Retroaction is not possible.
Fig. 3.1
Notes and General Information
- It is important to read this user manual carefully in order to understand the information and instructions. The Danfoss GD gas monitoring, control and alarm system may only be used for applications in accordance to the intended use.
- The appropriate operating and maintenance instructions and recommendations must be followed.
- Due to permanent product developments, Danfoss reserves the right to change specifications without notice. The information contained herein is based on data considered to be accurate. However, no guarantee or warranty is expressed or implied concerning the accuracy of these data.
Intended Product Application
The Danfoss gas detection system is designed and manufactured for controlling, for saving energy and keeping OSHA air quality in commercial buildings and manufacturing plants.
Installer’s Responsibilities
- It is the installer’s responsibility to ensure that all gas detection units are installed in compliance with all national and local regulations and OSHA requirements. All installation shall be executed only by technicians familiar with proper installation techniques and with codes, standards and proper safety procedures for control installations and the latest edition of the National Electrical Code (ANSI/NFPA70).
- The equipotential bonding required (also e.g. secondary potential to earth) or grounding measures must be carried out in accordance with the respective project requirements. It is important to ensure that no ground loops are formed to avoid unwanted interference in the electronic measuring equipment.
It is also essential to follow strictly all instructions as provided in installation guide/user guide.
Maintenance
- Danfoss recommend checking the GD gas detection system regularly. Due to regular maintenance differences in efficiency can easily be corrected. Re-calibration and replacement of parts can be realized on site by a qualified technician with the appropriate tools.
Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to products provided that such alterations can be made without subs already on order provided that such alterations can be made without sub sequential changes being necessary in specifications already agreed. All trademarks in this material are property of the respective companies. Danfoss and the Danfoss logotype are trademarks of Danfoss A/S. All rights reserved.
BC283429059843en-000101 | DKRCI.PS.S00.D1.02
© Danfoss | DCS (MWA) | 2018.10
Documents / Resources
 | Danfoss BC283429059843 Gas Detecting Sensors [pdf] User Guide GDIR.danfoss.com, BC283429059843 Gas Detecting Sensors, BC283429059843, Gas Detecting Sensors, Detecting Sensors |
