User manual

Transferring Data Using Communication Blocks

33002479 06 07/2008 147

Block Description

Function

Description

You can select one of 14 available network communication operations (see

Operational Function Codes, p. 151) using the MBP_MSTR function block.

Depending on the communication protocol you are using, you can have up to 16

MBP_MSTR function blocks active at the same time.

z Modbus Plus supports up to 4 blocks at the same time

z TCP/IP Ethernet supports up to 16 blocks at the same time

All function blocks use 1 data transaction path and require multiple cycles to

complete an operation.

EN and ENO can be configured as additional parameters.

Note: You must be familiar with the routing procedures of your network when

programming an MBP_MSTR function block. Modbus Plus routing path structures

are described in detail in the Modbus Plus Network Planning and Installation

Guide. If TCP/IP or SY/MAX Ethernet routing is implemented, standard Ethernet IP

router products must be used. A full description of the TCP/IP routing is provided

in the Quantum with Unity Pro TCP/IP Configuration User Guide.

Note: In FBD and LD sections, this function block can be used only on the program

level, i.e. not in derived function blocks (DFBs).

For technical reasons, an MBP_MSTR function block does not allow the use of ST

and IL programming languages.

Note: A TCP/IP communication between a Quantum PLC and a Momentum PLC

is possible only when only one read or write job is carried out in every cycle. If

several jobs are sent per PLC cycle, the communication stops without generating

an error message in the status register of the function block.

Example:

z you can send MBP_MSTR.Enable:=(HSBY_NOEPLCMSTR_ON) AND

(%SW61.1) AND NOT (%SW61.0)

z you can create a boolean variable, primary_state:=(%SW61.1) AND NOT

(%SW61.0), and insert it for executing the section