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GridScan/Pro SI
Stand-by mode
In this mode, the light curtain is inactive, no elements are scanned. The communication is active, and requests will be
answered. If the command Data: Full state (0x31) or Data: Reduced state (0x30) are requested, the state of light curtain
and elements responds as interrupted.
Alignment mode
In the alignment mode, the light curtain automatically sends an alignment value to align the system in the best position.
The alignment value is only available after an interrupted power-up and the alignment mode is activated (firts power-up
or activation by communication protocol).
10.1.2 System test (safety-relevant)
The test is provided by the communication protocol with command Safety: Test input (0x40) . The test input is active until
the first information message is sent. The test is successful if all elements switch to interrupted for at least one scanning
cycle and reactivate by the next information message.
10.1.3 System alignment
For a proper function, the emitter and receiver need to be mounted in line. The receiver has to be mounted at 180° to the
emitter. To optimize the alignment, a value between 0 and 65535 is available by the first start-up in the interrupted state.
As soon as the light curtain is free for the first time, the standard operation is available and the alignment mode is disabled.
To use the alignment mode a second time, it needs to be activated by the command Info: Request alignment mode (0x25) .
The system is installed in the best way, if the alignment value is as low as possible. If the value increases by rotating the
light curtain, the alignment gets worse and and the light curtain needs to be rotated in the other direction.
10.2 Safety function RS485 CEDES communication protocol
Data transmitted on the RS485 channel uses a safe, proprietary protocol which meets the requirements of SIL 2 as long as
the following checks are performed by the door control unit. If any of these checks fails, data are no longer safe according
to SIL 2 and the door control unit must initiate an appropriate safety related action.
1. Check timing of received data, as defined in Chapter 10.2.1.
2. Check integrity of received data, as defined in Chapter 10.2.2:
- Sequence counter must change as expected.
- Direction bit must be as expected.
- Transmitted CRC must match with the calculated CRC.
3. Check for internal fault, as defined in Chapter 10.2.3.
Important:
Request from the door control unit will only be responded if the data are valid. If the sequence counter, ID or the check
sum is incorrect no data will be responded and a new request is needed.
10.2.1 Check timing of received data
The timing of received data is part of the validation required for safe data transmission.
Parameter to check
Cycle time
(time expectation)
10.2.2 Check integrity of received data
The integrity of received data is part of the validation required for safe data transmission.
Integrity is validated with the sequence counter and CRC which is calculated over data including the sequence counter.
16
Action
Check if the messages are received within
the latency time.
Description
Detection of unacceptable delays, missing
messages or communication loss.
English
© CEDES | V 1.0
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