IBM 4685-L0D, Setup, Operation, And Service Manual

Page: 59 / 80

Message timing
The RS-232 scanner interface message transmission must conform to the specifi-
cations shown in Figure 4-8.
Error detection
There is no error detection.
Interface timing
Figure 4-8. RS-232 scanner interface timing
Notes:
1. The CTS sent or not sent, according to the configuration you have chosen.
2. If the CTS is sent, and is received at least t2 before the following Start Bit, only
one additional character is transmitted. If the CTS is received before an RTS is
sent, no characters are transmitted.
3. The minimum interval between transmitted characters is 0 ms.
Time Description Minimum Maximum
t1 Time from RTS sending to TxD start bit
(Note I) 1
µ
s 1 ms
t2 Set-up time from CTS receiving to TxD
start bit (Note 2) 1
µ
s N/A
t3 Time from CTS sending to TxD start bit 1
µ
s 5 ms
t4 Time from end of stop bit to RTS receiving
−
10
µ
s 500 ms
t5 Time from RTS receiving to RTS sending
of the next message 20
µ
s N/A
Chapter 4. RS-232 Scanner interface specifications
4-15