20 comm C connect to PLC5/40C

[abambang]

we're currently replacing starter mars with VFD powerflex700 with 20 COMM C communication adapter. we're use PLC5/40C. i read in this forum they're different version of controlnet which PLC5/40C version 1.25 and 20 COMM C higher version. i want to know is it any possibility to make connection between PLC to VFD ? or i should change communication adapter using 20 COMM R ?

 

[Ken Roach]

ControlNet Phase 1.25 controllers are very uncommon. Are you working on a Solar Turbines generator control system ?

20-COMM-C modules are compatible only with ControlNet Phase 1.5 controllers and network modules.

The Allen-Bradley Universal Remote I/O protocol, on the other hand, has been the same since 1977. Any RIO adapter (including the 20-COMM-R) is compatible with any PLC-5 controller.

 

[abambang]

i'm a DCS engineer and my company has a plan to change air starter to VFD on mars compressor solar turbine. right know i'm review this small project. so with 20 comm c communication adapter my PLC5/40C can communicate with the VFD? then i should not change the communication adapter to 20 COMM R ?.

 

[Ken Roach]

20-COMM-C modules are compatible only with ControlNet Phase 1.5 controllers and network modules.

PLC-5/40C = 1785-L40C = ControlNet Phase 1.25
PLC-5/40C15 = 1785-L40C15 = ControlNet Phase 1.5

Solar Turbines was one of the major users of ControlNet Phase 1.25 controllers, in particular the 1785-L40C controller, when ControlNet was introduced in the late 1990s.

Some of those controllers have been upgraded to "Phase 1.5" firmware, but most have not, which means that only ControlNet Phase 1.25 network devices (1794-ACN, 1771-ACN) can be used with the older controllers. All PLC-5C controllers and all 1771-ACN adapters can be upgraded, but some older 1794-ACN adapters cannot. As far as I know, only Solar Turbines is offering these upgrade services for equipment they provided. As far as I know, Rockwell Automation will not modify or upgrade a Solar Turbines system. You must contact Solar Turbines in San Diego, California, USA to find out.

The 20-COMM-C adapter for PowerFlex drives is a Phase 1.5 device only. It will not work with a PLC-5C controller that has Phase 1.25 firmware.

You absolutely must determine if your PLC-5C has Phase 1.25 or Phase 1.5 ControlNet firmware if you intend to modify any of the ControlNet components.

As you have suggested, the use of Remote I/O and the 20-COMM-R adapter for PowerFlex is a possible option for adding VFDs to this controller.