Allen Bradley Plc 5 Slot Addressing

October 31st, 2006, 11:57 PM
Hi all,
Current configuration of the PLC-5 chassis is as follows:
All dc DI cards are placed left-most position which are closest in the chassis to the PLC-5 processor. Then the dc DO cards. We didn't have any AI,AO cards at all, and there are some racks in the chassis which are blanked.
Now we need to expand our PLC system by additional dc DI/DO card, we need to just simple place those new cards into the blanked rack? Or we need to re-adjust the placement order in the chassis (such that all DI cards (current or new installed) placing the left-most position first)?
We found the placement order priority in the Allen-Bradley PLC-5 manual and they did mention we need to place all DI cards in the left-most position first.
Please help! Thank a lot!
Allen Bradley Plc 5 Slot AddressingAddressing

Allen Bradley Plc 5 80

Bradley

Plc 5 Allen Bradley

Q1: If there are no 'un-assigned' slots according to the addressing type, and no size of rack, then yes. The 'span' for chassis 1 is 1/0-1/5, meaning 6 words, which will cover the entire 12-slot chassis if 2-slot addressing is used. So my guess is 'yes'. Block Transfers use the 1st word assigned to the slot in question.