79
Intermec EasyCoder 201 II – Technical Manual
INTERFACES, cont'd.
The examples below illustrate two of four possible cases of the
printer or host computer being active transmitter or receiver, i.e.
being the supplier of the current to the loop.
PRINTER
CABLE
COMPUTER
+
-
+
-
Transmitter
Receiver
47 ohm
270
ohm
Pin 9
Pin 11
Pin 12
Pin 10
Pin 13
Pin 18
Pin 25
Pin 14
TXD+
TXD-
RXD+
RXD-
+
-
+
-
Transmitter
Receiver
47 ohm
270
ohm
Pin 9
Pin 11
Pin 12
Pin 10
Pin 18
Pin 25
TXD+
TXD-
RXD+
RXD-
Printer active transmitter/active receiver
Printer active transmitter/passive receiver
20 mA Current Loop
on "uart1:", cont'd.