Phoenix Contact IL MOD BK DI8 DO4-PAC Inline Bus Coupler

1 Description

The bus coupler with integrated I/Os is intended for use within a Modbus RTU/ASCII network and represents the link to the Inline I/O system. Up to 61 Inline devices can be connected to the bus coupler. The bus coupler supports a maximum of 8 PCP devices.

Features

• Modbus connection via 9-pos. D-SUB socket
• Electrical isolation between Modbus interface and logic
• 8 digital inputs, 4 digital outputs onboard
• Data transmission speed in Modbus of 1.2 kbps to 115.2 kbps (configurable)
• Rotary coding switches for setting the Modbus address and for configuration
• Supported Modbus addresses from 1 to 99
• Automatic detection of the transmission speed in the local bus (500 kbps or 2 Mbps)
• Shipbuilding and UL approvals

Valid from firmware version 1.03.

WARNING: Explosion hazard when used in potentially explosive areas. When using the terminal in potentially explosive areas, observe the corresponding notes. This data sheet is only valid in association with the IL SYS INST UM E user manual.

Make sure you always use the latest documentation. It can be downloaded at: phoenixcontact.net/product/2878696

3 Ordering Data

Main Product

Accessories

Documentation

4 Technical Data

Dimensions (nominal sizes in mm)

Width: 80 mm

Height: 119.8 mm

Depth: 71.5 mm

Note on dimensions: Specifications with connectors

General Data

Connection Data: Inline connector

Connection Data for UL approvals: Inline connector

5 Interface and System Limits

Interface: Modbus/RTU

Interface: Inline local bus

System limits of the bus coupler

Note: Observe the logic current consumption of each device when configuring an Inline station! It is specified in every terminal-specific data sheet. The current consumption can differ depending on the individual terminal. The permissible number of devices that can be connected therefore depends on the specific station structure.

6 Power Supply and Consumption

Bus coupler supply U_BC; Communications power U_L (7.5 V) and the analog supply U_ANA (24 V) are generated from the bus coupler supply.

Bus coupler supply (U_BC)

Communications power (U_L)

Supply of analog modules (U_ANA)

Main circuit supply (U_M)

Segment circuit supply (U_S)

Power consumption

Protection

NOTE: Electronics may be damaged when overloaded

Provide external protection for the 24 V areas U_BK, U_M, and U_S. If you are using an external fuse, the power supply unit must be able to supply four times the nominal current of the fuse. This ensures that it trips in the event of an error.

7 Digital Inputs and Outputs

Digital inputs

Digital outputs

Digital outputs behavior

Error messages to the higher level control or computer system

Mechanical tests

Conformance with EMC Directive 2014/30/EU

Noise immunity test in accordance with EN 61000-6-2

Noise emission test as per EN 61000-6-4

Approvals

For the latest approvals, please visit phoenixcontact.net/products.

8 Internal Circuit Diagram

The internal circuit diagram illustrates the connections between the microprocessor (µP), protocol chip (IB), power supply units (5V, 7.5V, 24V), digital inputs (DI1-DI8), digital outputs (DO1-DO4), and the Modbus interface. The diagram highlights electrically isolated areas labeled A (Modbus interface), B (Logic), and C (I/O).

Key:

• µP: Microprocessor
• IB: Protocol chip
• LED
• Optocoupler
• Power supply unit with electrical isolation
• Power supply unit
• RS-485 interface with electrical isolation
• PNP transistor
• Electrically isolated areas

9 Notes on Using the Terminal Block in Potentially Explosive Areas

WARNING: Explosion hazard. Please make sure that the following notes and instructions are observed.

Approval according to ATEX Directive 2014/34/EU: II 3 G Ex nA IIC T4 Gc X

Installation notes

The category 3 device is designed for installation in zone 2 potentially explosive areas. It meets the requirements of EN 60079-0:2012 + A11:2013 and EN 60079-15:2010.

• Observe the specified conditions for use in potentially explosive areas.
• At the time of installation, use an approved housing (minimum protection IP54), which meets the requirements of EN 60079-15. Within this context, observe the requirements of IEC 60079-14/EN 60079-14.
• The following work is only permitted in potentially explosive areas when the power is disconnected: Snapping the device onto the DIN rail, Removing the device from the DIN rail, Connection and disconnection of cables.
• Connect the DIN rail to the protective earth ground.
• For safe operation, the D-SUB connector must be screwed into the corresponding D-SUB socket. Repair any damaged connectors immediately.
• Only devices that are designed for operation in Ex Zone 2 and the conditions at the installation location may be connected to the circuits in Zone 2.
• Make sure that the maximum permissible current of 4 A flowing through potential jumpers U_M and U_S (total current) is not exceeded.
• When using the device in potentially explosive areas, observe the specifications in the application note AH DE IL EX ZONE 2 (German) / AH EN IL EX ZONE 2 (English).

10 Connecting Modbus, Supply, Actuators, and Sensors

7.1 Connecting Modbus

Connect Modbus to the bus coupler via a 9-pos. D-SUB connector (see ordering data). For the pin assignment, please refer to the figure and the table.

Figure 2: Pin assignment of the 9-pos. D-SUB female connector

7.2 Mains termination resistors

Using the SUBCON connector specified in the ordering data ensures that the cable termination meets the Modbus RTU/ASCII specification.

11 Terminal Point Assignments and Connection Example

7.3 Terminal point assignment of input and output connectors

Power connector (1)

Output connector

Input connector (3)

Input connector (4)

8 Connection example

Figure 4 shows a typical connection example for the bus coupler, illustrating the power supply connections (24 V DC for U_S and U_BK) and the Modbus RTU interface.

12 Local Status and Diagnostic Indicators

Figure 5: Local diagnostic and status indicators

13 Parameterization of the Hardware

10.1 Address setting

The address is set using two rotary encoding switches. The left switch sets the tens position, and the right switch sets the units position. Addresses can be set between 1 and 99. Figure 6 illustrates the address setting 74.

A valid address is applied on power up and cannot be modified during operation.

10.2 Parameterization via rotary coding switches

In addition to the address, various operating parameters can be set via the rotary coding switches. These parameters are read only upon a power-on reset. If the tens switch is set to a position not valid for an address (≥ 10), the bus coupler enters "Parameter setting" mode.

Default parameters are set upon delivery and after factory configuration reset. On a power-on reset, the bus coupler reads and saves the current operating parameter. Repeat for multiple parameters. The watchdog LED indicates parameter reading status: quick flash (reading), slow flash (accepted), very quick flash (invalid).

Example: To set "Disable Plug and Play" and "ASCII" operating parameters:

• Set "Disable Plug and Play".
• Perform a voltage reset.
• Once accepted, set "ASCII".
• Perform a voltage reset.

14 Parameterizing via Modbus Registers

Configuration can be modified via Modbus registers in addition to rotary coding switches.

All registers are 16-bit. New parameters are applied after a positive response. The last valid parameter record applies after power-up. Changing the baud rate also adjusts RTU framing times (t1.5, t3.5). For more details, visit www.modbus.org.

15 Modbus Telegram Watchdog and Plug and Play Mode

10.4 Modbus telegram watchdog (connection monitoring)

Monitors Modbus telegrams and triggers on correct reception. Can be enabled/disabled via rotary switches. Time set via register 1280 (0=disabled; 200ms-65000ms). Actions upon triggering depend on fault response mode (default: reset fault mode - set digital outputs to zero, freeze analog outputs, watchdog LED on). Settings modified by write access are applied on power-up reset, except for watchdog activation via register 1280, which is immediate.

The Modbus telegram watchdog does not operate during Plug and Play mode.

10.5 Plug and Play mode

Supports Plug and Play mode for starting local bus modules without a higher-level computer. Activated/deactivated via "ADDRESS" rotary switches (register 2006). Activated by default. Stores configuration retentively. Detects modules, checks function, and stores reference configuration. Deactivating prevents overwriting. If Plug and Play is disabled, the bus starts only if the configuration matches the saved one. If enabled, process data writing is rejected by exception; read access is possible. Deactivating PnP acknowledges reference configuration and enables process data exchange. If configurations differ, CO LED turns red; if they match, the bus enters RUN state. Options: Restore original configuration or activate PnP and restart.

16 Modbus Protocol

The Modbus protocol defines data exchange between a client and a server. It includes an Application Data Unit (ADU) comprising a Protocol Data Unit (PDU) with Function Code, Data, and Error Check.

Modbus RTU

RTU telegrams consist of Station address, Function, Data, and CRC. They are separated by end-of-frame times. RTU offers higher data throughput than ASCII.

Modbus ASCII

ASCII telegrams use start and end characters and are less time-critical.

12 Modbus functions

The protocol functions determine data read/write operations. Supported functions include:

• fc1: Read coils (digital outputs)
• fc2: Read input discretes (digital inputs)
• fc3: Read multiple registers (analog outputs)
• fc4: Read input registers (analog inputs)
• fc5: Write coil (digital output bit)
• fc6: Write single register (analog output)
• fc15: Write multiple coils (digital outputs)
• fc16: Write multiple registers (output registers)

17 Examples for Modbus Functions

Function code fc1 (Read digital outputs)

Details request, response, and error structures for reading digital outputs. An example shows reading outputs 20 through 38.

Function code fc2 (Read digital inputs)

Details request, response, and error structures for reading digital inputs. An example shows reading inputs 197 through 218.

Function code fc3 (Read analog inputs)

Details request, response, and error structures for reading registers. An example shows reading registers 108 through 110.

Function code fc4 (Read analog inputs)

Details request, response, and error structures for reading input registers. An example shows reading input register 9.

Function code fc5 (Write digital output)

Details request, response, and error structures for writing a digital output. An example shows writing output 173 ON.

Function code fc6 (Write analog output)

Details request, response, and error structures for writing a single register. An example shows writing register 2 to 0003hex.

Function code fc15 (Write multiple digital outputs)

Details request/response PDU structures and error codes for writing multiple outputs. An example demonstrates writing a series of 10 outputs starting with output 20, including binary value assignment.

Function code fc16 (Write multiple registers)

Details request/response structures and error codes for writing multiple registers. An example shows writing two registers starting with 2 to 000Ahex and 0102hex.

18 Modbus Tables

14.1 Process data

Modbus register tables provide information on process data location. Bit-oriented data typically precedes byte-oriented data.

Static table

The assignment of process data in static tables is illustrated by diagrams showing the physical layout and corresponding register addresses for data input (DI, AI) and data output (DO, AO).

Dynamic table

For dynamic tables, register areas are not fixed. The general order of process data is: DATA IN (bit-oriented), DATA IN (byte-oriented), DATA OUT (bit-oriented), DATA OUT (byte-oriented).

The assignment of process data in dynamic tables is also illustrated by diagrams showing the physical layout and corresponding register addresses.

19 Special Registers

14.2 Special registers

14.3 Description of special registers

Modbus telegram watchdog (connection monitoring), (1280): Valid values are 0; 200 ms to 65000 ms. Monitors Modbus telegrams, triggers on correct reception. Can be enabled/disabled via rotary switches. Time set via register 1280 (0=disabled). Actions upon triggering depend on fault response mode (default: reset fault mode - set digital outputs to zero, freeze analog outputs, watchdog LED on). Settings modified by write access are applied on power-up reset, except for watchdog activation via register 1280, which is immediate.

Fault response mode, (2002):

Net Fail reason, (2004): Used to read the reason after a Net Fail signal. For IL MOD BK DI8 DO4-PAC, the reason is connection monitoring watchdog failure (value 000Dhex in register 2004).

Command register (command word), (2006): Activation/deactivation of Plug and Play mode is performed by Bit 0 (0=deactivated, 1=activated). Bit 1 acknowledges Net Fail; Bit 2 acknowledges peripheral fault.

Status register (status word), (7996): Bit 0 indicates error status (0=error, 1=no error). Bit 1 indicates Net Fail status (1=Net Fail occurred, 0=not occurred). Status word values: 0 (error), 1 (no error), 2 (Net Fail).

Local bus diagnostic status register (7997): Each bit indicates a state of the local bus master. Error bits (USER, PF, BUS, CTRL) are detailed in the diagnostic parameter register. If an error bit is set, the diagnostic parameter register is rewritten; otherwise, it is 0000hex.

PCP registers (6020 - 6093): Divided into Communication registers (for data exchange) and Configuration registers (for invoke ID, index, subindex). Refer to IBS SYS PCP G4 UM E user manual for details. The terminal supports eight PCP devices.

Local bus diagnostic parameter register 1 (7998): Contains error location (e.g., device number 0.3).

Local bus diagnostic parameter register 2 (7999): Contains additional information about error codes. Refer to IBS SYS FW G4 UM E user manual for details.

20 PCP Registers

PCP registers are categorized into Communication registers and Configuration registers. The table below outlines the mapping for different Communication References (CR).

Example: To read object 5FE0hex of an IB IL RS 232-PAC with communication reference 4, first set configuration registers (6041-6043) with FC 16 command (e.g., 6041 index: 5FE0hex, 6042 subindex: 0hex, 6043 invoke ID: 0hex). Then use fc3 command to read 29 words via communication register 6040. Modbus functions are used for read/write access to PCP indexes. Accessing reserved registers generates an exception response.