i950 ES: SDI monitoring no longer works after using the 'Muting' function with a pending SDI error
Corrected from:
i950 Extended Safety (ES): from V01.03.06
Response of the new version:
SDI error is cleared by activating muting
During muting, a violation of the prescribed direction of rotation leads to the SDI error again (because SDI monitoring is always active in standard operation and is not activated by S-Bus)
After completion of the muting, a violation of the prescribed direction of rotation again leads to the SDI error
If, on the other hand, SDI is triggered via S-Bus (control bits "SDIpos" or SDIpos"), the monitoring functions again after the muting has ended.
What happens?
If SDI monitoring is active in standard operation in the safe parameter set, activating the function Muting in case of SDI error (0xFF8E or 0xFF8F) results in SDI no longer being monitored.
The corresponding "observed" bit is then no longer set and the monitoring is no longer triggered in the event of a prohibited direction of rotation. This applies both during the muting and after the muting has ended.
SDI monitoring is active in standard operation with the following settings:
0x28BA/1 "SDI: Monitoring standard operation" = 1 "Positive direction enabled"
(only positive direction of rotation allowed, status bit "SDIpos observed" always set, error 0xFF8E "SDIpos - Wrong direction) OR
0x28BA/1 "SDI: Monitoring standard operation" = 2 "Negative direction enabled"
(only negative direction of rotation allowed, status bit "SDIneg observed" always set, error 0xFF8F "SDIneg - Wrong direction)
When does the behaviour occur?
In the application, the SDI function is used and the SDI function detects a violation of the SDI tolerance limits (SDI error condition).
The user uses the muting function to acknowledge the error, deactivate any other functions and move the drive if necessary.
In this state, the monitoring of the SDI function is no longer active.
This also applies to an SDI function that is permanently activated by parameterisation, although the functions that are active by parameterisation should generally not be influenced by muting according to the specification.
Muting is limited to safety bus and safe inputs/outputs according to the specification.
In the further course, the SDI function is not reactivated without further ado with the deactivation of the muting function.
However, the behaviour depends on whether an edge change occurs with regard to the request of the SDI function after the muting function is cancelled.
The following case distinctions are to be considered:
SDI permanently active by parameterisation: Without intervention by the user, such as a restart, the SDI function remains deactivated, as there is no edge change with regard to the request for the SDI function.
SDI is requested via the safety bus and this is blanked by muting: After the muting function is cancelled, an edge change occurs with regard to the request for the SDI function. The SDI function is thus active again.
SDI is requested via a safe input and this is blanked by muting: After the muting function is cancelled, an edge change occurs with regard to the request for the SDI function. The SDI function is thus active again.
SDI is requested via the safety bus and muting only affects the safe inputs: After the muting function is cancelled, there is no edge change with regard to the request for the SDI function. The SDI function is thus not active again without user intervention.
SDI is requested via a safe input and muting only affects the safety bus: After the muting function is cancelled, there is no edge change with regard to the request for the SDI function. The SDI function is thus not active again without intervention by the user.
SDI is requested via a safe input and another input is muted: After the muting function is cancelled, there is no edge change with regard to the request for the SDI function. The SDI function is thus not active again without intervention by the user.
For error evaluation, a general distinction must be made between two types of application.
Applications in which a drive changes the direction of movement cyclically: In this case, the SDI function must also be activated and deactivated cyclically. In this case, the edge change described above occurs with regard to the request of the SDI function. In these cases, the described error is only relevant until the next change of direction.
Applications in which, in principle, only one direction of movement is permitted: If an SDI error occurs in this case, cases a), d) and e) can lead to a permanent failure of the SDI function. However, the user must ensure that the muting function is only used during commissioning and for maintenance purposes. This is shown accordingly in the operating instructions. If there is an SDI fault, the user's/commissioning engineer's work will focus precisely on this function. It is to be assumed that in this case in particular, careful commissioning and a final function test involving the effectiveness of the SDI function will be carried out.
