S500 modules as remote I/O (CS31 / MODTCP)
I'm planning to use S500 DI524 and DO524 (32-channeled) as remote I/O.
In case of CS31 bus every node is limited to 120DI/120DO (240 I/O in total) or 7 modules, so maximum I/O I can get with DI524/DO524 is 7modules*32cahnnel=224 I/O.
Same time, CS31 communication interface module has their own I/O. For example, DC551-CS31 has 8 DI and 16 DC. In total with 7 modules it will 224+8+16=248 I/O what exceeds limitation of 240 I/O per node. Those 8 excessive I/O will not be accessed by CPU and user program?
Is it possible to use S500 as MODTCP I/O? There are some mentions about CI521-MODTCP and CI522-MODTCP on the ABB site but they are absent in latest catalogue. If CI521-MODTCP and CI522-MODTCP are active product what kind of master coupler should be used from the left of the CPU? Is it possible to use built in CPU Ethernet interface for communication with S500 I/O via CI521(CI522)-MODTCP?
If built in CPU Ethernet could be used for S500 MODTCP communication, is it possible to use this interface same time simultaneously for SCADA to PLC communication?
Many thanks in advance.
Voted best answer
You could use a PM554 or PM564 as modbus rtu slaves instead of the DC5xx CS31 modules. It is my experience that it is just as reliable and you have a cpu that dont stop functioning if the bus is down and the price is a little lower.
The CI521 and CI522 are hard to configure. You need to write the config in the program. It takes programming space from the other things you need to do. They work briliantly but are hard to configure until you get the hang of it.
The price of the CI52x are about the same as an eCO cpu with ethernet. So again I would recommend the PM5xx-ETH instead of the CI52x.
You can use your built in ethernet for more than 1 thing. The ethernet has from 9 and up of free spaces(sockets). That means you can have 9 different things connected at the same time. FX: 1 for ModbusTCP, 1 for scada and 1 for UDP if you like. You can use them as you like. You can also with 1 socket connect to many different slaves, but not at the same time.
thanks for reply. Yes, I thought about smallest eCo CPU as replacement of DC551-CS31 because eCo CPU has low price and allows connection more than seven modules (this fact also optimizes price as far I need less eCo than DC551-CS31). Truly speaking, I prefer CS31 as hardware based communication while Modbus-RTU between main CPU and eCo's is software based. But in any case I keep this case in mind.
By the way, configuration of DC551-CS31 with seven modules DI524 or DO524 will not work because more than 240 I/O is defined and PS501 configuration shows error.
About CI521-MODTCP/CI522-MODTCP - they are absent in Automation Builder 1.0. How I can configure them?
sorry, one more question regarding CI521-MODTCP and CI522-MODTCP but in connection with non-ABB Modbus/TCP capable processor, for example - Schneider's Modicon Premium with integrated Ethernet port. Do you know if it is possible to configure/connect/communicating from Unity Pro of Modicon Premium with CI521-MODTCP/CI522-MODTCP or one have to write communication code like in your Automation Builder example?