Unit 3: Installation
GL408-412e Operator’s Manual
3-9
READY/BUSY INTERFACE SIGNALS
SIGNAL SIGNAL DEFINITION
FGN (Frame Ground)
TxD (Transmit Data) - Data from the printer to the host computer. Sends X-On/X-Off characters or status
data (bi-directional protocols).
RxD (Receive Data) - Data to the printer from the host computer.
RTS (Request To Send) - Used with Ready/Busy flow control to indicate an error condition. RTS is high
and remains high unless the print head is open (in this case, RTS would return to the high state after
the print head is closed and the printer is placed back online) or an error condition occurrs during
printing (e.g., ribbon out, label out).
CTS (Clear To Send) - When this line is high, the printer assumes that data is ready to be transmitted. The
printer will not receive data when when the line is low. If not being used, it is be tied high.
DSR (Data Set Ready) - When this line is high, the printer will not receive data. This line must be high
before data is transmitted. If not being used, it is to be tied high.
SGN (Signal Ground)
DTR (Data Terminal Ready) - This signal applies to Ready/Busy flow control. The printer is ready to
receive data when this pin is high. It goes low when the printer is offline, either manually or due to an
error condition, and while printing in the single-job buffer mode. It will also go low when the data in the
buffer reaches the buffer near-full level.
READY/BUSY CABLE REQUIREMENTS
DB9 HOST DIRECTION DB9 PRINTER
-- FGN (Frame Ground) Bi-Directional -- FGN (Frame Ground)
3 TxD (Transmit Data) To Printer 2 RxD (Receive Data)
2 RxD (Receive Data) To Host 3 TxD (Transmit Data)
6 DSR (Data Set Ready) To Printer 4 DTR (Data Terminal Ready)
5 SGN (Signal Ground) Bi-Directional 5 SGN (Signal Ground)
4 DTR (Data Terminal Ready) To Host 6 DSR (Data Set Ready)
8 CTS (Clear To Send) To Printer 7 RTS (Request To Send)
7 RTS (Request To Send) To Host 8 CTS (Clear To Send)
