Pixsys PL300 User Manual

1. Data Acquisition Module PL300

The PL300 is a powerful data acquisition module that serves as an I/O interface for Industrial terminals or SCADA systems. It measures temperature values using various thermocouples and thermoresistances, and acquires normalized signals via a 14-bit converter. The module features 6 digital inputs for alarm notices and 2 linear outputs (isolated 14-bit) capable of driving different types of transducers. Additionally, it offers twelve relay outputs (2 relays rated at 8A and 10 relays rated at 5A / 230VAC resistive).

A key advantage of the PL300, compared to PC boards, is its ability to be placed close to the plant, communicating with the central unit via RS485 or Current Loop 20mA (both galvanic isolated). This configuration enhances immunity to external noise and simplifies wiring. The module is designed and manufactured in compliance with current CE standards, meeting the safety requirements for both light and heavy industry.

General Features

Hardware Data

Software Data

1.2 Frontal Panel

The front panel of the PL300 features:

• 1. Plug Connector: For communication COM1, COM2.
• 2. LEDs:
  • RUN Green LED: ON when PL300 is operating. Fast flashing (0.2s ON / 0.2s OFF) indicates that the main program is unavailable and only the boot program is stored.
  • COM Yellow LED: ON for 50ms during serial port frame transmission. ON during programming (main program update).
  • OUT 1-12 Red LEDs: ON when the output is active.
  • IN 1-10 Green LEDs: ON when the digital input is active. Blinking indicates an analog input is out of range.
• 3. Slave Number: Indicates the slave number of the PL300 module.

1.3 Size and Installation

The PL300 module is designed for DIN rail mounting (EN50022). The dimensions are 160 mm width, 90 mm height, and 53 mm depth. Terminal blocks are clearly labeled for various connections including COM1, COM2, digital inputs, analog inputs (AN1-AN4), and RS-485/Current Loop connections.

Visual Description of Connections:

• COM1 (RS485): Terminals 25 (C - RS REF), 26 (A - RS485-), 27 (B - RS485+).
• COM2 (RS232): Terminals for TX and RX.
• Analog Inputs (AN1-AN4): Each input consists of positive (+), negative (-), and compensation (C) terminals. For example, AN1 uses terminals 22 (+), 23 (-), and 24 (C).
• Digital Inputs: Common positive signal for digital inputs (terminals 3, 6, 9, 18). These can be used to activate inputs or supply sensors.

1.4 Electrical Wirings

Detailed wiring information is provided for various connections:

1.4.1 Examples of sensor connections to analog inputs PL300

2-Wire Connection (0-20mA / 4-20mA):

• Connect the sensor's positive output to the analog input's positive terminal (e.g., AN3: 15).
• Connect the sensor's negative output to the analog input's negative terminal (e.g., AN3: 16).
• The common positive signal (terminal 18) can be used as the power supply for the sensor.

3-Wire Connection (0-10V):

• Connect the sensor's positive output to the analog input's positive terminal (e.g., AN2: 20).
• Connect the sensor's negative output to the analog input's negative terminal (e.g., AN2: 21).
• The common positive signal (terminal 18) can be used as the power supply for the sensor.

1.4.2 Example of connection to RS485 and to a Master unit

A daisy-chain connection for RS485 communication is shown, connecting multiple PL300 modules to a master unit. Shielded twisted-pair cable is recommended. A 220 ohm termination resistor is used at the end of the bus.

1.5 Select type of linear output

The PL300 has two linear outputs (OUT1, OUT2) configurable via software and dip-switches. To configure:

1. Disconnect power.
2. Remove the upper cover.
3. Set dip-switches SW1 (for OUT1) and SW2 (for OUT2) according to the desired output type:

• Logica 15V SSR
• 4-20 mA
• 0-10 Volt

Replace the cover and restart the PL300. Note: Dip-switches SW1-1 and SW2-1 are used for communication address setting, not output selection.

1.6 Communication address

Two dip-switches (SW1 and SW2) allow setting the module's address for communication with a master device. Up to four modules can be connected directly. For more than four modules, an offset parameter must be configured in Modbus word 5.

Module Address = Address Offset + Combination of DIP-Switches

To set the address:

1. Disconnect power.
2. Remove the upper cover.
3. Set dip-switches SW1-1 and SW2-1 as shown below. The resulting value is added to the offset value for the complete address.

Combinations for DIP=0, DIP=1, DIP=2, DIP=3 are illustrated with diagrams of the dip-switch settings.

Replace the cover and restart the PL300.

1.7 List of configuration parameters

Configuration parameters are stored in EEPROM and are retained after power loss. Each parameter can be written up to 100,000 times. Modifying parameters initiates a 2-second initialization of input reading and output rates.

Parameters are represented using hexadecimal digits, divided into 4 nibbles:

• 1st digit: bits 12-15
• 2nd digit: bits 8-11
• 3rd digit: bits 4-7
• 4th digit: bits 0-3 (LSB)

Analog Input Configuration (P-01 to P-04)

These parameters define the type of sensor connected to analog inputs AN1, AN2, AN3, and AN4.

Scale Limits (P-05 to P-12)

These parameters define the numeric limits for analog conversion for signals connected to AN1-AN4 (for current/voltage inputs).

Calibration (P-13 to P-20)

These parameters define the calibration for converting AN1-AN4 signals to correct reading mistakes. The formula is: Value = Value + (Value * GAIN calibration) / 100.0 + OFFSET Calibration.

Software Filter (P-21)

P-21: Software filter (1-20 sec) for conversion of AN1, AN2, AN3, AN4.

Linear Output Type (P-22, P-23)

These parameters define the type of linear output used. Dip-switches must be set correctly. Time for SSR output is set on P-24 (OUT1) and P-25 (OUT2).

Servo-Control Parameters (P-24 to P-31)

These parameters configure the servo-control and operating modes for various outputs (relay and SSR).

Relay State in Off-line Condition (P-32)

P-32: Defines the state of relays during communication failure with the MASTER for over 60 seconds. Each bit corresponds to a relay (Bit0 for U1, Bit1 for U2, etc.). Value 65535 disables this function.

1.8 Configuration of alarms for analog inputs

Each analog input can have two alarms configured, with operating modes defined by parameters P-57 to P-76. The following alarm types are available:

• Independent Alarm / Over: Alarm triggers when the signal exceeds a maximum threshold.
• Independent Alarm / Under: Alarm triggers when the signal drops below a minimum threshold.
• Deviation High Alarm: Alarm triggers when the signal exceeds a threshold plus hysteresis.
• Deviation Low Alarm: Alarm triggers when the signal drops below a threshold minus hysteresis.
• Band Alarm / Inside: Alarm triggers when the signal is within a defined band (between two thresholds).
• Band Alarm / Outside: Alarm triggers when the signal is outside a defined band.
• Deviation Low Alarm - Disabled at Starting: This alarm is disabled at startup and activates when the signal exceeds the alarm threshold plus hysteresis.

Visual diagrams illustrate the behavior of each alarm type relative to the signal, alarm threshold, and hysteresis.

1.9 Tuning (Automatic setting of PID parameters)

Tuning adjusts the controller's characteristics to match the process for optimal performance, aiming for:

• Stable, fluctuation-free control at the setpoint.
• No overshoot or undershoot of the temperature.
• Quick response to disturbances, rapidly restoring the temperature to the setpoint.

Tuning involves calculating and setting parameters such as:

• Proportional band: The range over which output power is proportioned.
• Integral time: Time taken to eliminate steady-state error signals.
• Derivative time: How strongly the controller reacts to the rate of change of the measured value.
• Servo-control time: Cycle time for time-proportioning output (not rated for motorized valve control).

1.10 Protocol Modbus RTU

The PL300 supports Modbus RTU for communication with SCADA systems or terminals. This enables parameter programming, I/O configuration, and reading of analog/digital inputs and outputs control.

Features of Modbus RTU:

• Baud-rate: COM1: 9600 baud (default), COM2: 19200 baud.
• Format: 8,N,1 (8 data bits, no parity, 1 stop bit) is the default.
• Supported functions: Includes reading/writing bits and words, with specific function codes (e.g., 0x01, 0x03, 0x05, 0x06, 0x0F, 0x10).
• Error codes: ILLEGAL FUNCTION CODE (0x01), ILLEGAL DATA ADDRESS (0x02), ILLEGAL DATA VALUE (0x04).
• Broadcast: Simultaneous writing to all connected slaves without an answer.
• Polling of unknown slave address: Uses address 0xFF; any connected slave answers.

A diagram shows the pinout for the PL300's COM1 plug (8-pin) for RS485 communication.

1.11 Addresses WORD/BIT PL300 for Modbus RTU

This section details the Modbus addresses for data handling (words and bits) by the PL300. It specifies read/write features and default starting values.

Data Storage Types:

• EEP: Stores values in EEPROM, retained after power failure.
• TAMP: Stores values in non-volatile RAM, retained for approximately 4 months after power failure.
• ?: Values not provided at PL300 startup.
• Numeric value: The value at PL300 startup.

WORD Addresses

BIT Addresses