When using a Unity Premium PLC, what function block would I use for retrieving diagnostic information from a Modbus slave device?
Issue:
Function block to use in a Premium PLC for retrieving diagnostic information from a Modbus slave device
Product Line:
Premium PLC, Unity Pro
Resolution:
The SEND_REQ function block is used for retrieving diagnostic and maintenance information from a Modbus slave device....
Function block to use in a Premium PLC for retrieving diagnostic information from a Modbus slave device
Product Line:
Premium PLC, Unity Pro
Resolution:
The SEND_REQ function block is used for retrieving diagnostic and maintenance information from a Modbus slave device....
| Modbus Request | Function Code / Sub Function Code | Communication Function |
|---|---|---|
| Exception status | 16#07 | SEND_REQ |
| Diagnostics | 16#08/16#xx | SEND_REQ |
| Event counter | 16#0B | SEND_REQ |
| Connection event | 16#0C | SEND_REQ |
| Slave identification | 16#11 | SEND_REQ |
The diagnostics and maintenance information are shown below:
| Designation | Function code / sub-function code |
|---|---|
| Read exception status | 16#07 |
| Echo | 16#08 / 16#00 |
| Initialize module | 16#08 / 16#01 |
| Read the diagnostic registers of the PLC | 16#08 / 16#02 |
| Change end of frame delimiter (ASCII mode) | 16#08 / 16#03 |
| Switch to listening mode | 16#08 / 16#04 |
| Reset counters | 16#08 / 16#0A |
| Number of messages received without CRC error | 16#08 / 16#0B |
| Number of frames received with CRC error | 16#08 / 16#0C |
| Number of exceptional responses | 16#08 / 16#0D |
| Number of messages addressed to the PLC | 16#08 / 16#0E |
| Number of broadcast messages received | 16#08 / 16#0F |
| Number of correct responses | 16#08 / 16#10 |
| Number of messages received in listening mode | 16#08 / 16#11 |
| Number of invalid characters received | 16#08 / 16#12 |
| Read event counter | 16#0B |
| Read connection event | 16#0C |
| Read identification | 16#11 |
Udgivet til: Schneider Electric Danmark
Brug for hjælp?
Produktvælger
Find hurtigt og nemt de rette produkter og det rette tilbehør til dine anvendelser.
Få et tilbud
Start din salgsforespørgsel online, så vil du blive kontaktet af en ekspert.
Find forhandler
Find den nærmeste Schneider Electric-distributør.
Hjælpecenter
Find supportressourcer til alle dine behov på ét sted.