GridScan/Pro SI
English
© CEDES | V 1.0
19
11. System timing (RS485)
The system transmits a message to the control unit after finishing of the scanning cycle (t
CYCLE
) if a request has been
received during the scanning cycle. The status information of the single elements or light curtain will be updated during
every main loop. In the streaming mode, the updated data is transmitted after a full main loop. If an additional request is
received, the request is answered first, followed by the streaming information.
Important:
The GridScan/Pro SI can handle only one request per t
CYCLE
.
t
LAT
t
CYCLE
message
n
message
(n+1)
t
frame
t
CYCLE
Figure 11:
System timing overview
Symbol
Parameter
Min.
Typ.
Max.
Unit
t
CYCLE
- Sampling cycle time at 22 elements
- Transmission cycle time at 22 elements
18
30
40
ms
t
CYCLE
- Sampling cycle time at 60 elements
- Transmission cycle time at 60 elements
48
62
76
ms
t
frame
Duration for message transmission
0.9
1.2
1.8
ms
t
LAT
Latency time at 22 elements; time from
starting scanning until the message is
transmitted (t
CYCLE
+ t
frame
)
18.9
31.2
41.8
ms
t
LAT
Latency time at 60 elements; time from
starting scanning until the message is
transmitted (t
CYCLE
+ t
frame
)
48.9
63.2
77.8
ms
Response time
Power-up time
1,700
ms
Response time
2 × t
LAT
ms
Test response time
2 × t
LAT
ms
Table 1:
System Timing (RS485 at 115.2 kBit/s)
