Despatch Protocol Plus Modbus Communications - Manual (Page 36)

Chromalox Instruments and Controls
A-51643 Rev. 6 10/06/03 30
Table 11: Protocol
TM
Plus Diagnostic Register Bit Assignment
Bit # Description
0 NA
1 NA
2 EEPROM Data Error
3 NA
4 NA
5 NA
6 NA
7 A/D
8 Not Used – Loop Error
9 Not Used – Tune Error
10 Not Used -- Available for Application Specific Support
11 Not Used -- Available for Application Specific Support
12 Not Used -- Available for Application Specific Support
13 Not Used -- Available for Application Specific Support
14 Not Used -- Available for Application Specific Support
15 Not Used -- Available for Application Specific Support
Example: Return the diagnostic register from slave device 2 (with an EEPROM error).
Query Response
Field Name Data Field Name Data
Slave address $02 Slave address $02
Function $08 Function $08
Sub-function hi $00 Sub-function hi $00
Sub-function lo $02 Sub-function lo $02
Data hi $00 Data hi $00
Data lo $00 Data lo $04
CRC $---- CRC $----
5.3.1.4 [08 04] Force Listen Mode Only
Forces the slave into Listen Only Mode. This isolates it from the other devices on the network, allowing
them to continue communicating without interruption form the addressed slave. No response is returned.
When the slave enters this mode, all active communications are turned off. All messages broadcast or