Re: [foxboro] Use of FBM232 to communicate with 20 devices via one IP address

Ahmed
Fundamentally the 232/233 TCP FBMs are designed to not work through a
bridge/gateway
I had a long battle with IPS and only achieved a PER 2731 we all know
how usefull a PER is.

There are two issues that I know of
IP addresses must be unique in the ecb's, the IP/Device notation does
get around this but we noticed strange behaviour like scan rates being
the same, we also tried OCTAL, HEX and dotless decimal Ipaddresses to
fool the configurator syntax and talk to lots of devices in the end our
FCP went single so we gave up.

Assuming your HVAC PC behaves like a bridge and conforms to Modbus
protocol if one of your slaves is faulty the bridge will send an
exception back to the host saying cannot perform transaction as
requested, the FDSI driver will assume that any response is a good
response and will not show the slave as failed, this is also true for
writes to the slave (this is the bit that turned up in the PER)

Good luck
Shaun
 
 
_______________________________________________________________________
This mailing list is neither sponsored nor endorsed by Invensys Process
Systems (formerly The Foxboro Company). Use the info you obtain here at
your own risks. Read http://www.thecassandraproject.org/disclaimer.html
 
foxboro mailing list:             http://www.freelists.org/list/foxboro
to subscribe:         mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
to unsubscribe:      mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave

Other related posts: