Modbus and Profibus for SLC and CLX

[Scada Tom 0]

Need a Modbus card for a SLC 5/05, Prosoft makes one, I have used them before, will I be OK with Prosoft? Also for a compact logix 5370L1, that uses point I/O, any recommendations on a Profibus card Thanks

[Ken Roach 194]

You seldom go wrong with Prosoft. I've been using their Modbus modules for many years, and the MVI46-MCM module has a long reputation. Remember that the SLC-5/05 does have Modbus RTU Master capability on the serial port. For Profibus and a 5370 L1 controller... that's a tall order. I'm not aware of any Profibus device that connects to the POINTBus backplane. You're probably going to need a standalone network device that connects to both EtherNet/IP and Profibus. I like the QTS AN-X product, which is also sold and supported by Prosoft.

[Ken Roach 194]

An addendum; Prosoft does sell one of QTS's Profibus products (it's the low-profile black box) but also has a strong line of their standalone ProLinx gateways that support Profibus DP.

[Scada Tom 0]

I need to clarify this is Modbus TCP, will the serial port on the SLC 5/-5 work with it?

[Ken Roach 194]

Thanks for the clarification. No, the SLC-5/05 serial port (Channel 0) only supports Modbus RTU serial Master. The Ethernet port does not support Modbus/TCP. The MVI46-MNET module is what you want for Modbus/TCP connectivity on the SLC-5/05, or you can use a Modbus/TCP to EtherNet/IP gateway device. Unless I'm building a large number of machines and need only a small feature set, I tend to default to Prosoft modules. If my feature set is uncertain or the amount of capacity is unknown, I'm usually glad I bought the full power platform.

[Scada Tom 0]

An Update, the equipment I want to connect to has a Modbus RS485 card already installed. If I go Modbus TCP/IP I have to get a license, and loose the Ethernet port as it becomes Modbus (Ethernet is used for cellular radio comm) What's a suggested method to get Modbus RS485 into a SLC 5/05 PLC

[Ken Roach 194]

Is the connected equipment a Modbus RTU Master, or a Modbus RTU Slave ? If the connected equipment is a Modbus RTU Slave, your SLC-5/05 serial port can be a Modbus RTU Master. You can use an RS-232 to RS-485 converter (I like B&B Electronics for those) that is appropriate for the signal type on the connected equipment. You will program MSG instructions in the SLC. Make sure your particular SLC is new enough to have Modbus RTU functionality in the firmware. Modbus RTU Master was added to the SLC-5/05 as part of the Series C FRN 11 firmware in 2008. All SLC-5/05 controllers can be firmware upgraded, but it is a chargeable item from RA. Contact your distributor for details. If the connected equipment is a Modbus RTU Master, you will need a Modbus RTU Slave of some type for the SLC-5/05 controller. The Prosoft MVI46-MCM module is the most common and popular one one the market.

[mohssen 0]

If the built-in RS-232 channel on your SLC 5/05 PLC is free, you can use a converter: RS-485 to RS-232. you can use I-7520 module: http://www.icpdas-us...r.html?r=mohsen Good luck!