IBM 4685-L0D Setup, Operation, And Service Manual page 59

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
Time Description
t1 Time from RTS sending to TxD start bit
(Note I)
t2 Set-up time from CTS receiving to TxD
start bit (Note 2)
t3 Time from CTS sending to TxD start bit
t4 Time from end of stop bit to RTS receiving
t5 Time from RTS receiving to RTS sending
of the next message
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.
Minimum
1 µs
1 µs
1 µs
−10 µs
20 µs
Chapter 4. RS-232 Scanner interface specifications
Maximum
1 ms
N/A
5 ms
500 ms
N/A
4-15