GE GFK-1541B manual Commreq Function Block and Command Block, Comm REQ Sysid Task

3

COMMREQ Function Block and Command Block

This section describes the programming structures common to all Communications Requests: the COMMREQ Function Block and the Command Block.

The COMMREQ Function Block

The Communications Request is triggered when the logic program passes power to the

COMMREQ Function Block.

(Enable ) -------------

(Command Block address) -

(Rack/Slot Location of	-
the Ethernet Interface)
(Task value)	-

COMM

REQ

IN FT

SYSID

TASK

-OK (Series 90-70 PLCs only)

-Function Faulted (logic)

Each of the inputs and outputs are discussed in detail below. Remember that the Command Block address points to a location in memory that has been set up as the Command Block.

Enable: Control logic for activating the COMMREQ Function Block.

IN: The location of the Command Block. It can be any valid address within a word-oriented area of memory (%R, %AI, or %AQ for the Series 90-30 Ethernet Interface and the Series 90-30 CPU364) (%R, %AI, %AQ, %P, or %L for the Series 90-70 Ethernet Interface (Type 2)).

SYSID: A hexadecimal word value that gives the rack (high byte) and slot (low byte) location of the Ethernet Interface. For the Series 90-30 CPU364, this must always be set to 0001 to specify rack 0, slot 1. Note that if using GE Fanuc’s VersaPro PLC software, the leading zeros in this hexadecimal word value are not displayed on-screen; for example, 0004 will appear as 4.

Examples:

Rack	Slot	Hex Word Value
0	4	0004H
3	4	0304H
2	9	0209H
4	2	0402H

Note

The Series 90-70 Ethernet Interface (Type 2) is supported only in the main PLC rack (rack number 0).

3-6 TCP/IP Ethernet Communications for the Series 90™ PLC User's Manual– May 2002 GFK-1541B