Rockwell Automation T3831 ICS Regent Communications Package for Winterpret - Manual (Page 9)

Communications Package for W INTERPRET (T3831)
P D - 6 0 4 1 M a r c h , 0 6
9
templates in each Regent provide a complete definition of the
entire GPL network configuration.
When the GPL communications are active (see Connect
Network, starting on page 22) each Regent monitors the
activities of the GPL network for the types of errors listed in
Table 1. A brief explanation accompanies each type of error.
Table 1. Guarded Peer-Link Communications Errors.
Communications Error Explanation
Parity The communications module UART detects a
parity error for character.
Framing The communications module UART detects a
data framing error.
Character over-run The communications module UART detects a
character over-run.
Packet CRC The Regent validates the CRC for a received
packet.
Intercharacter time-out The Regent detects an intercharacter time-out
condition (5 character times).
Packet echo time-out The Regent detects that a node has not started
to transmit a response to a poll request in the
allotted time (20 milliseconds).
Remote activity time-out The Regent reports an error when no
communications activity occurs on a GPL port for
allotted time (2 seconds).
When the Regent detects errors on the GPL communications,
it reports these errors using system variable control relays.
Internally the Regent filters these faults to mask transient or
intermittent failures. When a fault occurs repeatedly, then
fault bits are set and certain fault handling responses may
occur.
For example if a Regent fails to receive data from a particular
node on the network, a fault bit will be set and the GPL input
data variables associated with that node will be set to their
configured final values.
GPL System Variables
There are 49 system variable control relays that are defined
for GPL status and fault reporting. These variables should be
monitored as appropriate in the application programs or
operator interface to notify plant personnel about the status of