Technical data

Linkage with PLC
CP 486 ⋅ 00/14 VIPA GmbH 151
6.4.2.6 Read Job Status
With this function, the status of an earlier started job can be called. For read jobs, variable and block
read jobs, this function copies data to a specified address to the CP, if the job status is 'finished
without error'.
Register
high In low Out
AX $20/$30 a_nr status
SI offset
DS segment
fn function number for status call
$20 for read jobs
$30 for write jobs
a_nr job number
offset offset of data address (in AT)
to be specified only for read jobs (variables and block).
segment segment of data address (in AT)
to be specified only for read jobs (variables and block).
status < 0 job finished with error
error messages of PC are added with FF00h.
1 job still in process
2 job status not defined
3 job finished without error
The following procedure is advisable for the status call:
- If the job is still "in processing", the status function has to be called as long as the status
changes.
- Concerning write jobs (bank 3): if the job was "finished without error", then the data were
written to the PC. For block elements, the bank has been released.
- Concerning read jobs (bank 2): If the job is 'finished without error', and a pointer was
specified for the data, the data will be copied to the specified address in the AT. Depending on
the specified data size, an exchange of bytes will be executed, if neccessary. The job block
will be released, in order to enable the execution of new jobs. If the address NULL (0:0) is
specified as a pointer, no data will be copied, but the job will be released as well.
- If the job status is 'not defined' the job was already finished earlier, but was not overwritten by
a new job. If this job was a read job and a pointer unequal to NULL was specified, the data
will be copied to the specified destination address.
- If the job is "finished with error", then the job block was enabled if a read job or a block job is
concerned.