Reference travel to cams
When referencing to cams, the offset is reset when a reference switch is passed. The cam can be connected via safe digital inputs or provided as a bit in the process output data of the CSA31A.
Reference travel must be enabled via a safe digital input or via the safe process output data. The use of a safe digital input has priority over the bit via the process output data, i.e. if the "Reference travel" function is assigned to at least one safe digital input, no referencing to the bit of the process output data takes place. Activation is performed using a logical "1" on the F-DI or on the set bit in the safe process data. If 2 cams or a redundant reference switch are used, 2 safe digital inputs must be parameterized as single-channel and the "Reference cam" function must be assigned to both. Using non-equivalent switching reference switches is not permitted. The reference switches are to be designed as NC contacts.
In the case of redundantly designed reference switches, two separate switches must be used. A two-channel switch cannot be used as 2 reference cams. Furthermore, it must be ensured that there is no crossfault in the cabling of the two F-DIs, or both switches must be connected to different F-SSx sensor supply lines.
The following parameters are relevant for reference travel:
- Reference offset
- Maximum speed
- Cam source
- Maximum tolerance with 2 cams
- Direction of movement
Safe reference travel is to be started from the non-safe area. At the start or during movement, reference travel must be activated via the "Reference travel" bit or via the safe digital input with "Reference travel" function assignment.
During reference travel, the reference cam must be intentionally passed with the parameterized direction of movement. The parameterized maximum speed must not be exceeded. When leaving the reference cam in the parameterized direction of movement, a rising edge is detected, which performs the referencing and sets the bit "Referenced".
If the reference cam is passed over against the parameterized direction of movement, the reference travel is terminated with an error. Especially with 2 reference cams, it must be ensured that leaving the reference cam changes the direction of movement after both cams provide a low signal.
For encoder 1, encoder 2 or encoder 3, the position is set to the reference offset for which the reference travel type "decoupled reference travel" is parameterized.
No referencing data is saved if the reference travel is interrupted. All the encoders that are to be referenced via reference travel are not referenced afterwards. The "F-PI_Referenced" signal is afterwards logically "0".
