Datamax M-class Mark II Operator's Manual page 76

Each GPIO pin function is detailed in the table below:
Signal
Pin #
Name
1 Vcc
2 Printer Fault
3 Spare
Start of Print
4
(SOP)
End of Print
5
(EOP)
6 & 8 Signal Ground
7 +24 VDC
[1]
Given relative to the printer.
[2] The operation of this multi-function port is configuration dependent. For GPIO operation, disable all optional
functions not used (i.e., Present Sensor and Cutter) and set GPIO to "YES" (or on display-equipped models set
GPIO Device to "APPLICATOR"). Use the Configuration Set command (<STX>Kc), or program the selections on
non-display models via the "Printer Setup Menu List" or on display-equipped models via the "Menu System."
Pin 3 should be pulled to +5VDC. In additional, connections
for the external Start of Print control can either be directly
made to Pin 4 of the Option Port (or Main PCB connector)
using a TTL-level input, or via an interface circuit (similar
to the one shown). For more information, see the table
below.
V max
in
V
IH
V
IL
I
OH
I
OL
V
OH
V
OL
2
M-Class GPIO Port Connections and Functions
Signal
Signal
Direct
State
[1]
ion
+5 VDC
Output
2.5 Amp (fused)
Low Output
Reserved Input
Programmable Input
Programmable Output
Ground N/A
1.6 Amp (fused) Output
M-Class Sample SOP Circuit
GPIO Port Specifications
5.5 VDC maximum input into any pin
3.8 VDC minimum (high level input voltage)
1.65 VDC maximum (low level input voltage)
-8 mA typical, - 25 mA maximum (high level output current)
8 mA typical 25 mA maximum (low level output current)
I = -8 mA, minimum 3.8 VDC
OH
I = 8 mA, maximum .44 VDC
OL
[2]
Signal Description
Printer +5 VDC
Goes low upon printer detection of a fault condition.
Must be pulled high (see sample SOP circuit, below).
When active, will begin print. Recommend only setting
this signal to ACTIVE LOW. When ready to print a
label, the applicator should hold this signal low for at
least 50ms – or until EOP goes not active. See sample
SOP circuit, below.
Signifies the end of the print process. Can be
monitored to initiate next Start of Print sequence.
Minimum signal time 30ms.
Ground
Printer +24 VDC
GPIO Connector Pin Number
Appendix B –GPIO Port
Vcc 1
1K O
1K O
Spare 3
SOP 4
Gnd 8