10 TROUBLESHOOTING
Turn off/clear command
Turn off/clear command
Read command
(c)Examples of programs that initialize displayed LED and communication error information
The following shows examples of a program that reads error codes when errors described in (1) above occur in an interface on the CH1 side and initializes the displayed LED and communication error information. Incorporate the necessary part of the program.
(Input/output signals X/Y00 to X/Y1F of the Q series C24)
1)When data is communicated using the MC protocol
Reads LED and communication error information from address 201H.
Reads switch setting error description from address 203H.
Reads data transmission/reception results from address 256H to 258H.
Requests initialization of error information on the
CH1 side and clearing of error codes in the buffer memory.
Requests initialization of error information on the CH1 side and clearing of error codes in the buffer memory.
Check the error codes and take corrective action according to Section 10.2.
2)When data is communicated using the non procedure or bidirectional protocol
Reads LED and communication error information from address 201H.
Reads switch setting error description from address 203H.
Reads data transmission/reception results from address 257H to 258H.
Writes initialization request such as for displayed LED to address 0H.
Requests initialization of error information on the CH1 side and clearing of error codes in the buffer memory.
Check the error codes and take corrective action according to Section 10.2.
REMARK
When data is communicated using the MC protocol, the displayed ERR. LED may not be turned on if the Q series C24 sends an NAK message to the external device in response to the command message.
Error codes (see Section 10.2) corresponding to the error content when the NAK message is sent back to the external device are stored in the following areas. (when communicating with an A compatible 1C frame, the error codes differ from the transmission error code.)
When checking error codes transmitted by the PLC CPU, incorporate the following program (in case of the interface on the CH1 side).
Reads transmission error codes from address 25AH.
Clears error codes.
Check the error codes and take corrective action according to Section 10.2.
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