Chapter 12 Communication; Rs-232C Interface (Qb30-Sr) - Denso QB30-SR User Manual

Chapter 12 Communication

12.1 RS-232C Interface (QB30-SR)

With the RS-232C interface being selected, the scanner uses asynchronous data transmission and communicates with the host
computer or external equipment via the RS-232C. You can set various communications conditions using the command,
QR-coded parameter menu or configuration software (QB Setting). Code data read is transferred in the following format.
(1) Communications protocol
You can select either non-acknowledge mode or ACK/NAK mode.
Non-acknowledge mode (default)
If the CTS signal is at a high level (Enable transmission), the scanner transmits code data read.
Note: The configuration software (QB Setting) provides CTS timeout settings from 100 ms to 9.9 s in 100-ms increments and
two CTS signal control choices Yes and No.
ACK/NAK mode
If the CTS signal is at high level (Enable transmission), the scanner transmits code data read. After that, the scanner waits for
and then processes a response. If the response is an ACK, the scanner normally ends the transmission; if it is a NAK, the
scanner transmits the code data again.
Note: The command and configuration software (QB Setting) provide CTS timeout and ACK/NAK response settings each
from 100 ms to 9.9 s in 100-ms increments.
(2) RTS signal control protocol
You can select either the scanner ready mode or the data ready mode.
Scanner ready mode (default)
The RTS signal goes High and stays at a high level when the scanner is ready to communicate at power on. Make sure that the
RTS signal is at a high level when transmitting a command from the host to the scanner.
Data ready mode
The RTS signal goes High before the scanner transmits data to the host and goes Low after the data transmission is completed.
Commands can be transmitted from the host to the scanner regardless of the level of the RTS signal. However, there is a short
time when commands cannot be transmitted to the scanner after power has been turned on.
(3) Transmission speed
There are six transmission speeds available, ranging from 4800 bps to 115200 bps (default: 38400 bps).
(4) Characters
Characters that the scanner transfers are all ASCII codes. The frame format has the following parameters.
Data bits: 7 bits or 8 bits (default)
Parity: Odd, Even, or None (default)
Stop bits: 1 bit (default) or 2 bits
Note: When data contains binary data or 2-byte codes, selecting "7 bits" for the data bits transfers the 2-byte codes with the
most significant bits trimmed.
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