Foxboro-SLC5/04 communication

Greetings all.

We have a PLC (SLC5/04) network successfully hooked up to our DCS (Foxboro I/A) via gateway devices (Integrator 30).

However, we lose the communication between the two systems after a power failure (though both are independently operating) and have to reset the communication link in order to restore connection (taking the integrator off-line and then back on-line via SMDH).

Foxboro rep states that the reset would not be required if the PLC could accommodate a heartbeat monitor, something SLC5/04 cannot. Is that correct? Is there a firmware upgrade that will permit the monitor? Any suggestions to eliminate this nuisance task?

Thanks,

Thom

I think the Integrator 30 has serial port on it, so it's likely connected to the SLC's Channel 0 serial port. Is this correct ?

I can't imagine that the Integrator 30 supports some DF1 protocol function that the SLC-5/04 doesn't. Ask your Foxboro rep precisely what he means by "heartbeat monitor".

I have three SLC 5/04's connected to a Foxboro DCS via an integrator 30 that is connected to a KF2 that sits on the DH+ network. While the 504's do not support the heartbeat option, I have never experienced the problem you listed.
However, my integrator 30 and KF-2 are on a UPS, and very seldom lose power, but the SLC's do and when they come back up, communication is resumed without any intervention. The system has been in place for about 7 years without a glitch.

How exactly is your Equipment Control Block (ECB) configured? I assume you are using an ECB15. How about your ABSCAN block, are you using polled mode or event driven mode? In even driven mode, the PLC data sent via message instruction must match the Foxboro ABSCAN block configuration exactly, else the Integrator30 will mark the PLC as failed. I suggest you have at least one polled ABSCAN block, when an Integrator 30 first starts up if it has a heartbeat function defined, it tries to establish comms with the PLC, it will also do this if you have at least one polled ABSCAN block.

I recommend you obtain and read Foxboro Document:
B0193RG - Integrators for Allen-Bradley Controllers.

It should be on you FoxDoc CD.


So back to Ken Roach's question, are you connected directly to the 504 or are you using a KF2 and DH+?

I was just looking through the Integrator manual, there is a note at the bottom of page100, that says 5/04's with firmware Rev. 15 or earlier do not support the Heart beat function, but later firmware revisions do. So updating the firmware on your SLC might be an option.

Basically the heart beat function is really a loop communication test that runs on an average of every 16 seconds, during normal conditions, and anytime the integrator is rebooted, or re-configured.


Also I forgot to ask earlier, is this a redundant system?

Sorry for being a bit blunt...but why not invest in a UPS.... hell we have both our factories instruments and PLC on a 6000VA UPS...

Huh. SLC-5/04's are currently shipping with firmware revision 10, so I wonder what the Foxboro documents are referring to.

I'll bet the "loop test" is a PCCC Echo that would be executed by a directly-connected PLC-5 controller but isn't passed on or executed by the 1770-KF2 interface module.

Sounds like Ken Moore is the right guy for this question. Great info, KM !