Black Box SW927C, SW928C, SW929C, SW925AE manual Connecting to DEC LN03 Laser Printer, RS-422 Cables

MODULAR SMART SWITCH

A.7 Connecting to DEC™ LN03 Laser Printer

The LN03 outputs its “printer ready” signal via pin 11, and so the wiring for the serial data cable is slightly different from those shown earlier. Switch bank 2, switch number 6, on the LN03 should be set to ON. This ensures that the “printer ready” signal is HIGH when ready and LOW when not ready, and not vice versa.

MODULAR SMART SWITCH

A.8 RS-422 Cables

The pins and connector types used for RS-422 communication vary widely between devices. Standard cables therefore do not exist. Connect the cable as shown in Figure A-8. For systems using XON/XOFF handshaking, only RXD +, RXD -, TXD +, and TXD - need to be connected.

Modular Smart Switch end	DEC LN03 end
25-Pin socket connector	25-Pin plug connector
2	3
3	2
5	11
7	7
20	6

Modular Smart Switch end		Communicating
25-Pin socket connector		device
HSOUT-	9	-ve
HSOUT+	10	+ve
RXD-	11	-ve
RXD+	12	+ve
HSIN-	15	-ve
HSIN+	16	+ve
TXD-	13	-ve
TXD+	25	+ve

Flow control in

Transmitted data out

Flow control out

Received data in

Figure A-7. DEC LN03 Serial Cable Pinning.

Figure A-8. RS-422 Cable Pinouts.

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