ICP DAS USA CAN-8823, User Manual

Page: 112 / 198

CAN-8x23 user’s manual (Revision 3.20, Ma r/08/2012) ------ 112
Step 4. Even the AI input value has been changed according the AO value, the
RxPDO will not respond automatically in the CAN-8423. Therefore, users need
to use the RTR message from the 2nd TxPDO to read back the AI value.
11-bit COB-ID (bit)
RTR
Data
Length
8-byte Data (byte)
Func Code Node ID
10 9 8 7 6 5 4 3 2 1 0 0 1 2 3 4 5 6 7
0 1 0 1 0 0 0 0 0 0 1 1 0 00 00 00 00 00 00 00 00
PDO
consumer
PDO consumer
(CAN-8x23)
COB-ID
: 0x281
Step 5. The feedback value for AI is 5V.
11-bit COB-ID (bit)
RTR
Data
Length
8-byte Data (byte)
Func Code Node ID
10 9 8 7 6 5 4 3 2 1 0 0 1 2 3 4 5 6 7
0 1 0 1 0 0 0 0 0 0 1 0 8 00 40 FD FF FD FF FD FF
PDO
consumer
PDO consumer
(CAN-8x23)
COB-ID
: 0x281
L
: 8
PDO-msg
: 00 40 FD FF FD FF FD FF
The first two bytes are for AI channel 0. The others are for AI channel
1, 2, and 3. The feedback AI0 value is 0x4000. All the other AI
channels are 0xFFFD. Users need to transfer this AI0 value to float.
The I-
87017’s input float range is set to -10V ~ +10V and the input
hex range is from 0x8000 (-32768) to 0x7FFF (32767). The value
0x4000 (16384) can be transferred by using the following equation.
 
 
     
V
V V V FloatValue
001 . 5
10 10 10
32768 32767
32768 16384

    






 
 
