Which products are affected?
9300 servo cam profiler V7.1
Applications
Cam drives or standard servo drives connected in master frequency coupling via DFIN,
electrical shaft function via master frequency connection or directly at a TTL encoder.
Description
In order to ensure the signal evaluation of TTL signals read in at terminal X9 a monitoring function has been implemented. If the P19 error message is evaluated, it can be detected whether the system dependent signal limitation inside the DFIN function block has been reached. The error message can be parameterised as 'Trip' or 'Warning' and deactivated under code C1292. According to the default setting 'Warning' is selected.
The evaluation can be made via Lecom by means of error number 169. Inside the application the monitoring function can be linked via the Monit function block.
If the monitoring is activated the MONIT-P19 is set and reset immediately automatically when being configured as warning or if the function is deactivated as soon as the limitation is stopped.
The signal limitation occurs dependent on the pulse frequency entered and the DFIN constant (C0425) set.
The limitation is generally executed at the pulse frequency of 500 kHz.
In addition the limitation is specified by an internal scaling factor resulting from the setting under C0425.
Example for a pulse frequency of 250 kHz and an encoder constant of 256 inc/rev:
Limitation = Pulse frequency x 2^(6 – [C425])
X > 32767 = 250 kHz = 1000 inc/ms x 2^(6 –0)
X > 32767 = 64000 inc/ms
Since the X-value calculated is larger than 32767 a limitation would result from the calculation example above. Thus it is to be noticed that a master frequency signal of 250 kHz and a DFIN constant of 256 inc/rev are not to be applied. The DFIN constant is to be changed to 512 inc/rev.
The limitation occurring leads to pulse losses of the master frequency signal at DFIN-OUT with reference to the input signal applied outside the device. As a result, a position drift between servo axis and upstream encoder or drive occurs.
