![background image](http://html1.mh-extra.com/html/curtis/3301t/3301t_manual_2699991053.webp)
6 — CANopen COMMUNICATIONS
pg. 47
Curtis Model 3301T Digital Instrumentation – September 2021
NODE IDS
The 3301T’s node ID is specified with the CAN Node ID parameter. The default node ID is 0x2E.
If the Curtis Electronic Code Switch (ECS) is on the CANbus, the ECS CAN Node ID parameter
specifies its node ID. Both parameters are on the
.
BAUD RATE
The 3301T’s baud rate is specified with the CAN Baud Rate parameter on the CAN menu. The default
baud rate is 250 Kbps.
MESSAGE CAN-IDS
The 3301T’s CAN messages are identified by 11-bit CAN IDs. The 3301T does not use 29-bit
CAN IDs.
EXPEDITED SDOS
The least significant byte of an expedited SDO is known as the
control byte
. The following table
describes the control byte fields:
7
6
5
4
3
2
1
0
Command Specifier
0b
n
e
s
The following list describes the control byte:
• The
Command Specifier
field indicates the SDO’s transfer type, which is described in the
following table:
Transfer Type
Value
Write data to a device
001b
Confirm a write
011b
Request data from a device
010b
Device responds with requested data
010b
Abort SDO
100b
• Bit 4 is always 0b.
• The values of bits 0–3 depend upon whether the SDO transfers data. If the SDO does not
transfer data, these bits are always 0b. If the SDO transfers data, the bit values are as follows:
–
n
indicates the number of unused data bytes.
–
e
= 1b, which indicates the message contains data.
–
s
= 1b, which indicates that the
n
field specifies the number of unused data bytes.