andyhart21
Member
Good afternoon, I am hoping someone out there can help me with a query I have about Siemens S7-300 I/O addressing.
We have an S7-400 PLC system with 17 x S7-300 remote I/O racks distributed around the plant. A need has arisen to add another 16 channels of DI to an existing I/O rack. If I do not have enough physical space (it is very tight) to add another 16ch DI at the end of the rack, my thoughts were to replace one of the existing 16ch DI's with a 32ch DI.
My question is, how will Step 7 allocate addresses to this 32ch DI? Will the first 16 channels be automatically addressed to the same as the old 16ch DI, and the second 16 channels be allocated new addresses? I hope this is the case as the existing code obviously uses the original 16 channels.
Also, what is the limit for adding I/O to a rack? Is it just a case of connecting a new module (if this is the way I go) with a bus connector and configuring it in the hardware configurator? I have never changed a module for a different type or added new I/O before so this is new ground for me, I have only ever changed like-for-like. The configuration on this rack at present is as follows:
PS307 PSU
SIMATIC ET200M / LINK
SIMATIC ET200M / LINK
SM321 16ch DI
SM322 16ch DO
SM322 16ch DO
SM331 8ch AI 4-20mA HART
Thanks in advance
Andy
We have an S7-400 PLC system with 17 x S7-300 remote I/O racks distributed around the plant. A need has arisen to add another 16 channels of DI to an existing I/O rack. If I do not have enough physical space (it is very tight) to add another 16ch DI at the end of the rack, my thoughts were to replace one of the existing 16ch DI's with a 32ch DI.
My question is, how will Step 7 allocate addresses to this 32ch DI? Will the first 16 channels be automatically addressed to the same as the old 16ch DI, and the second 16 channels be allocated new addresses? I hope this is the case as the existing code obviously uses the original 16 channels.
Also, what is the limit for adding I/O to a rack? Is it just a case of connecting a new module (if this is the way I go) with a bus connector and configuring it in the hardware configurator? I have never changed a module for a different type or added new I/O before so this is new ground for me, I have only ever changed like-for-like. The configuration on this rack at present is as follows:
PS307 PSU
SIMATIC ET200M / LINK
SIMATIC ET200M / LINK
SM321 16ch DI
SM322 16ch DO
SM322 16ch DO
SM331 8ch AI 4-20mA HART
Thanks in advance
Andy