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ObjectC 100
Programmer's
Guide
22
http://csa.cedes.com/
© CEDES Safety & Automation AG
Table 49: Response examples
Byte
Description
Value
Byte structure
ACK
06 Hex
0000 0110
Inv.
Address
(DIP switch)
= 255-1 = 254
(FE Hex)
1111 1110
Byte 1
Command
00
0000 0000
Byte 2
Command
13 Hex
0001 0010
Byte 3
Data
1E Hex
0001 1110
Byte 4
Data
1E Hex
0001 1110
Byte 5
Data
00
0000 0000
Byte 6
Data
00
0000 0000
Byte 7
Data
00
0000 0000
Byte 8
Data
00
0000 0000
ETX
03 Hex
0000 0011
3.1.4.
Timing (RS485)
Example for a Baud rate of 19'200 Baud and 1 Stop bit:
t
pd
t
question
t
answer
Question
( Master
Light curtain )
Answer
( Light curtain Master )
Figure 8: Timing of RS485 communication
Baud rate 19200 1 Bit = 52.08 µs.
1 start bit + 8 data bits + 1 parity bit + 1 stop bits = 11 bits = 572.92 µs
t
question
11 bytes = 4.583 ms
t
pd
This time window is dependent on the command number. As a minimum it lasts approx. t
pd
= 5 ms.
When using a light curtain with 254 beams and the command ‘trigger standard scan’, the time will
increase to approx. t
pd
= 55 ms.
T
response
11 bytes = 4.583 ms