Introduction

In X80 EIO drops, Modbus slave messages received by the BMXNOM0200 module are transferred to the X80 EIO adapter module (BMXCRA31210 or BMECRA31210). The adapter module forwards the message to the CPU.

To configure the BMXNOM0200 as a Modbus RS-485 RTU slave in an X80 drop, use these firmware versions and Control Expert Hardware Catalog devices:

Module

Firmware version

Control Expert Hardware Catalog device

BMXNOM0200

SV ≥ V1.5

BMXNOM0200.4

BMXCRA31210

or

BMECRA31210

SV ≥ V2.14

BMXCRA31210 (SV >=2.10)

or

BMECRA31210 (SV >=2.10)

The BMXNOM0200 module is configured differently in an M580 X80 drop than Quantum RIO drop, and is compatible with M580 BME•58••40 CPUs.

Installing a BMXNOM0200.4 Module

To install a BMXNOM0200.4 module in an X80 drop, follow these steps:

Step

Action

1

Install the CPU module on the local rack.

2

Install the adpater module BMXCRA31210 (SV >=2.10) or BMECRA31210 (SV >=2.10) on an X80 drop.

3

Install the BMXNOM0200.4 module in the X80 drop.

Supported Protocols

For the BMXNOM0200.4 module:

  • Channel 0 supports RS-232 or RS-485.

  • Channel 1 supports only RS-485.

Declaring the BMXNOM0200 module as a BMXNOM0200.4 module in Control Expert allows you to configure the module for:

  • Modbus RTU slave on RS-485

    NOTE:

    • Only Modbus RTU is supported as slave protocol.

    • Only RS-485 is supported when Modbus slave is selected.

  • Modbus Serial RTU and ASCII Master on RS-232 and RS-485

  • Character mode

Hot Standby

The CPU Main IP address swaps in the case of a PAC switchover. The Modbus requests are still forwarded to the primary CPU.

NOTE: The Modbus client application manages the repetition of requests in case of a message loss that could occur during a PAC switchover.

Maximum Configuration

The maximum configuration of the BMXNOM0200.4 module includes the following elements:

Element

Maximum configuration

Master channel

Four (4) per configured drop with a maximum of 36 expert channels per drop.

NOTE: Each configured channel of the BMXNOM0200.4 module counts as an expert channel.

Drop

Six (6) BMXNOM0200.4 per drop.

NOTE: With M580 CPU OS version ≤2.40, the maximum number of BMXNOM0200.4 per drop is limited to four (4).

M580 system

Thirty-one (31) BMXNOM0200.4

Modbus frame length

256 bytes

Supported Modbus Function Codes

This table lists the supported Modbus function codes (FC):

Binding to ->

Modbus FC:

Variable type

Code

Function

01

%M

0X

Read coil status (output bit)

02

%M

1X

Read input status (input bit)

03

%MW

4X

Read holding registers

05

%M

0X

Force single coil

04

%MW

3X

Read input register

06

%MW

4X

Write single register

15

%M

0X

Write multiple coils

16

%MW

4X

Write multiple registers

23

%MW

4X

Read/write multiple registers

Accessing the Channel Configuration Screens

To access the channel configuration screens of the BMXNOM0200.4 module, follow these steps:

Step

Action

1

In the Control Expert Project Browser , open the BMXNOM0200.4 module.

2

Select the channel to configure. By default:

  • Channel 0 is configured with the Character mode link function.

  • Channel 1 is configured with the Modbus link function.

NOTE: Some parameters are not accessible and are grayed out.
NOTE: Refer to the Modicon X80, BMXNOM0200 Serial Link Module, User Manual for details on these communication protocols.

Configuring Slave Modbus Link Communication

This table shows the default parameter values for the Modbus slave configuration screen:

Configuration parameter

Default value

Type

Slave

Slave number

1

Physical line

RS-485 only

Signals

RX/TX only

Transmission speed

19200 bits/s

Delay between frames

2 ms

Data

8 bits only

Stop

1 bit

Parity

Even