User manual

IEC61131 User and Reference Manual
April 22, 2008
607
Polling DF1 PLCs
All DF1 PLCs, except the PLC-5/VME, will support some portion of the basic commands
implemented.
AB PLC
Unprotected
Read
Unprotected
Write
Protected
Write
Protected
Bit Write
Unprotected
Bit Write
MicroLogix
1000
4


SLC500
1,3


SLC5/01
1,3


SLC5/02
1,2,3


SLC5/03
2,3


SLC5/04
2,3


1774-PLC





PLC-2





PLC-3
5





PLC-5
5





PLC-5/250
5




PLC-5/VME
Notes
1
At the protocol level these commands convert and send the slave word address as a byte
address. The SLC500, 5/01 (and 5/02, prior to Series C FRN 3) treat this byte address as if it
were a word address in the SLC500. This means that the (desired word address)/2 must be
specified for the Slave Register Address in MSTR or master_message. Note that this always
results in an even starting word address in the slave SLC. (E.g. Slave word address of 7
specified in MSTR accesses SLC word address 14.)
2
The SLC5/02, 5/03 and 5/04 have a status selection bit (S:2/8) which allows selection of
either word or byte addressing when interpreting only these commands. (Setting SLC bit
S:2/8 = 1 selects byte addressing so that, for example, a slave word address of 7 specified
in MSTR accesses SLC word address 7.)
3
These commands can access SLC memory only in the CIF or Common Interface File: N9.
See further details in section 12-15 of the SLC500 Instruction Set manual.
4
These commands can access MicroLogix memory only in the CIF or Common Interface
File: N7. See further details in section 12-15 of the MicroLogix 1000 Instruction Set manual.
5
These commands can access memory only in the CIF or “PLC-2 compatibility file”: N7. See
further details in section 16-7 of the PLC-5 manual.