How devicenet bricks act – GE Industrial Solutions OKCV3000CN DeviceNet User Manual
Page 32
GEl- 100343
5.3. HOW DEVICENET BRICKS ACT
To use the DeviceNet Bricks you must remember the following:
0
-
there are 3 Bricks:
+
CFIX is the Brick on the master card
+
RFIX and WFIX are Bricks on the slave card
-
the slave reads/writes in the FWA;
-
the master reads/writes its own IVAR and decides where to write/read in the slave-
-
the master acts as follows
:
-
during IDLE-to-READY, CFIX Bricks is analyzed and some values are fixed
-
during IDLE-to-READY, DeviceNet system software starts to establish connections with the slave mapped
in parameters “SlaveMapLow” and “SlaveMapHig”
-
in READY state no Bricks program is executed
-
in READY state DeviceNet system software transmits/receives some meaningless words of FWA to main-
tain the I/O connections opened (only with connections already established)
-
during READY-to-RUN DeviceNet system software deletes every meaningless transmission still pending
-
in RUN state the Bricks program is executed. When a CFIX is executed, transmission over the network is
done (or scheduled if the transmitter is busy), only if the connection is established
-
during RUN-to-READY the pending transmissions are deleted
-
in READY state DeviceNet system software transmits/receives some meaningless words of FWA to main-
tain the 110 connections opened
-
during READY-to-IDLE DeviceNet system software deletes all connections still open;
-
in IDLE no master communication occurs
-
the slave acts as follows
:
-
regardless of the DGFC state (IDLE/READY/RUN) DeviceNet system software answers to master, if con-
nection is established
AUENT,oN:
a
DGFC can be master and slave simultaneously.
k2Z
HOW TO EXCHANGE I/O DATA