Allen-Bradley 1407-CGCM, Руководство пользователя, Страница: 131 / 252

Rockwell Automation Publication 1407-UM001H-EN-P - November 2014
CGCM Unit Software Interface #HAPTER
Two types of connection-related services are involved in the configuration of the
CGCM unit:
•
Forward Open - When a connection is first established, for instance when
the module profile is first configured or the CGCM unit is powered on, a
Forward Open service is executed. The ConfigRcvd and
UnschdWriteRcvd bits initial states are de-asserted. The controller writes
the Configuration data table automatically, and when the CGCM unit
accepts this write, the ConfigRcvd bit is set. When the ConfigRcvd bit is
set, the user program logic rung that controls the Unscheduled Write
message is enabled. When the CGCM unit accepts the Unscheduled
Write, the UnschdWriteRcvd bit is set.
•
A Null Forward Open is executed when all these conditions are met:
– A connection is already established.
– A change to the Configuration or Unscheduled Write data tables is
made in the module profile tabs.
– Appy or OK is clicked.
The controller attempts to write the Configuration automatically. If
excitation is enabled, the configuration write is rejected. If excitation is not
enabled, the CGCM unit accepts a valid configuration write. Regardless of
excitation status, the CGCM unit de-asserts the UnschedWriteRcvd bit
during the execution of a Null Forward Open. This action re-enables the
user program logic rung that controls the Unscheduled Write message.
When the CGCM unit accepts the Unscheduled Write, the
UnschdWriteRcvd bit is set.
With the UnschedWriteRcvd bit asserted, the CGCM unit begins processing
Scheduled Write (Output) data and is ready for normal operation based on
configuration and outputs received. The CGCM unit ignores any Scheduled
Write (Output) data if the UnschedWriteRcvd bit is not asserted.
#ONFIGURATION3UMMARY
These are the configuration changes to the CGCM unit.:
•
The CGCM unit accepts Configuration data only when excitation is
disabled and all configuration data is in the correct range.
•
The CGCM unit accepts Unscheduled Write data regardless of the
excitation state provided that all Unscheduled Write data is in the correct
range.