Modbus Master/Slave Communications Interface Module

3100-MCM

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

Features

The first major upgrade of the Modbus module product began shipping in February, 1997. The major upgrade features are highlighted below:

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:

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.

User Manuals and sample ladder logic examples are available from the download page on our web site at www.prosoft-technology.com

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

This product supports the following general capabilities:

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)

Support for the storage and transfer of up to 4000 registers to/from the PLC

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
• Parity: None, odd, even
• Stop: 1 ro 2
• Baud: 300 to 38.4K
• Mode: RTU or ASCII-7 bit or ASCII-8 bit

Backplane current load:

• 3100 module for PLC : 0.65 Amps

Hardware Specifications

• Backplane current load
• 3100 module for PLC
  - 0.65 A

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

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

• Relative humidity
  - 5-95% (w/o 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
  - RS232/422/485 jumper selectable
  - RS422/485 screw termination included (two per module)
  - RS-232 hardware handshaking (RTS/CTS, DTR)
  - 500V 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: