WARNING: This function cannot be used in a task if the co_send_sdo()/co_asw_sdo() functions are also present in the task.
This function is used to read CoE fieldbus objects (the object defined by 'stru.objCode + stru.subIndex' on the device identified by stru.rid is read).
It can read more data types than the analogous function co_robj().
Reading can be done in pass-through mode or in blocking mode (usable only in tasks 1-:-8).
Pass-through mode means that the function must be continuously called and simultaneously tested the current state of the task.
Blocking mode means that the function is invoked and returns only when it has completed the read operation.
The function returns a result on the state of execution.
Syntax |
i32 co_robj (stru_coe_obj stru, destination) |
|---|---|
stru |
Structure name of type stru_coe_obj |
destination |
Contains the information received. destination must be an object compatible with the data being read (if reading a VISIBLE STRING, destination will be of type string, if reading an OCTET_STRING it will be a byte array or structure) |
Result |
Variable of type i32 containing the result. See pass-through mode and/or blocking mode |
Validity |
Rule, Task |
Note |
•Set stru.phase = 1 to initialize the read •The read command is sent to the remote device and a response is expected. The variable stru.phase is changed. •Waiting for response. •Response is received with a positive result. The value read is written to destination. RTE changes stru.phase = 4. •Receive response with negative result. RTE changes stru.phase = 0. o-2, communication handler busy o-3, communication handler crash (restart) o-5, command to a device not present(stru.rid) o-6, no operation running. stru.phase not initialized o-12, illegal value of objcode(alarm 9900 arg 12) o-13, illegal value of subindex (alarm 9900 arg 13) o-14, illegal value of datatype (alarm 9900 arg 4/arg 14) o-15, illegal value of datalen (alarm 9900 arg 5/arg 15) o-16, illegal value of phase (alarm 9900 arg 6) o-21, destination not specified (alarm 9900 arg 16) o-22, destination changed (alarm 9900 arg 32) o2, command for which a positive response has already been received, value available in destination o>2, SDO error code, see table below |
•Set stru.phase = -1 to perform the read •The read command is sent to the remote device and a response is expected. The variable stru.phase is changed •Waiting for response. If the response does not arrive within a maximum of 3 seconds, the function exits with an error (timeout, returns -2) •Receiving response with a positive result. The value read is written to destination. RTE changes stru.phase = 4. •Receive response with negative result. RTE changes stru.phase = 0. o-2, communication handler busy o-3, communication handler crash (restart) o-4, blocking mode not allowed in current task(stru.phase = 1) (rule, ladder). Command not accepted o-5, command to a device not present(stru.rid) o-6, no task running. stru.phase not initialized o-12, illegal value of objcode(alarm 9900 arg 12) o-13, illegal value of subindex (alarm 9900 arg 13) o-14, illegal value of datatype (alarm 9900 arg 4/arg 14) o-15, illegal value of datalen (alarm 9900 arg 5/arg 15) o-16, illegal value of phase (alarm 9900 arg 6) o-21, destination not specified (alarm 9900 arg 16) o-22, destination changed (alarm 9900 arg 32) o2, command for which a positive response has already been received, value available in destination o>2, SDO error code, see table below |
Example of use:
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