Modbus Communications Module Master or Slave

3150-MCM

The Modbus Communication Module allows the user to easily configure each of its two ports as either a Modbus Master or Slave.

Features

Command Polling Time - Master Driver

Each command can now be configured with a polling time to effectively control the frequency of execution. The timer has a resolution of one (1) second and each command can be configured up to 65535 seconds.

Command Control Mode - Master Driver

The command control mode is the most frequently requested feature. In this mode, the Modbus Master driver only executes commands in the command list upon receiving an enable bit from the ladder logic. The module returns done and error bits as part of the regular command status information returned to the ladder allowing commands to be sent only when desired.

Event Initiated Write Commands - Master Driver

The Modbus Master driver in the MCM module supports the execution of event driven write commands. This type of support provides the ladder logic program with a very high speed method of sending Modbus write commands to a slave.

Pass-through Mode - Slave Driver

• The pass-through mode allows a Modbus Slave port to pass write commands received from a host directly across the backplane for handling by ladder logic. This feature is easily implemented in ladder logic. There are certain situations where this functionality can be useful. Some of these situations include:
• The slave needs to know when it has been written to.
• The acceptance of data may require some conditioning.
• The host's write data registers must overlap the read register space.

Routing Mode - Slave Driver

The Routing Mode allows a Modbus Slave port to 'route' commands received from a host to the master port. A list of up to six (6) routed slave addresses can be entered in the configuration table. Whenever a host read or write command is received on the slave port that matches one of the six addresses, the command is routed out the master port and the response is routed back to the slave port.

Simple to Use

All module setup and operating control is performed over the backplane through simple ladder logic and data table configuration. The only software necessary is a standard ladder programming package.

Port Configuration

The two Modbus ports are configured independently, allowing the module to operate in any one of the following configurations:

• Once configured, the module will perform all protocol related functions on a stand alone basis.

Installation, Set Up and Operation

The ProSoft module installs in any slot in a local rack. The product's capabilities are enabled and controlled with simple ladder logic and data table initialization.

Applications

The Modbus Communication Module can be found in many industrial sectors and in the following applications:

• Foreign device
• Data concentrator
• Pipelines and offshore platforms
• Food processing
• Mining
• Pulp and paper

Functional Specifications

• Up to 100 entries in the command list, each fully configurable for function, slave address, register to/from addressing and word/bit count (master port)
• Continuous polling of command list (master port)
• Event driven bit and register write commands (master port)
• Full radio, modem and multi-drop support
• Supports RS-232C, RS-422 and RS-485 interfaces
• Communication error codes and counters returned to ladder logic (slave port)
• Communication error codes returned to ladder logic on a per command basis (master port)
• The following Modbus features have been implemented in both configurations
  - RTU mode (binary) with CRC-16
  - ASCII mode with LRC error checking

• Broadcast commands
• 125 word reads and writes
• Floating point data movement supported
• Function codes supported
  1: read output status
  2: read input status
  3: read multiple data registers
  4: read input registers
  5: force single coil (write single bit)
  6: preset (write) single data register
  15: force multiple coils (write multiple bits)
  16: preset (write) multiple data register

• Configuration via simple ladder logic (example provided with each product)
• Communication parameters
  - Address: 1 to 247
  - Ports: Modbus RTU Master or Slave, 1 stop bit, no parity, 300 to 19200bps
  - Mode: RTU or ASCII-7 bit or ASCII-8 bit

• Backplane current load
  3150 module for SLC: 5 V @ 0.15 Amps and 24V @0.040 amps

Hardware Specifications

• Backplane current load
• 3150 module for SLC
  - 5V @ 0.15 A
  - 24 V @ 0.040 A

• Operating temperature
  - From 0° C to 60° C (32° F to 140° F)

• Storage temperature
  -From -40° C to 85° C (-40° F to 185° F)

• Relative humidity
  - From 5% to 95% (without condensation)

• LED indicators
  - Module Status
  - Backplane transfer status
  - Serial port TX/RX activity LED
  - Serial port error LED status

• Application Serial ports
  - DB-25F - 3100 module
  - DB-9M - 3150 module
  - RS232/422/485 jumper selectable
  - RS422/485 screw termination included (two per module)
  - RS-232 hardware handshaking (RTS/CTS, DTR)
  - 500 V Optical isolation from backplane

Ordering Information

Distributors:
Place your order by email to orders@prosoft-technology.com:, fax to +1 661-716-5101.

Sales and Support: