132  A-Class 
GPI/O A (J1)  
 
Four dedicated inputs are available for control of printer functions. These inputs 
require no external pull-ups, are designed to interface to open-collector outputs and 
accept totem pole outputs from +4.5 to + 26 VDC. Optical isolators are available to 
provide isolation. Two print control circuit examples are given below. 
 
 
 
For direct inputs –  
 
Use the printer’s +5VDC and Ground to supply the 
devices interfacing to the GPI/O A inputs (as 
shown, right). 
  
 
 
GPI/O A - J1
3
4
5
6
1
Start of Print
Slew Label
Toggle/Pause
Reprint
Ground
 
 
 
 
 
 
 
 
 
For isolated inputs – 
 
To provide galvanic isolation for the GPI/O A 
inputs, remove jumper JMP 9 then supply an 
external +5VDC source voltage to Pin 2, and 
remove jumper JMP 8 then supply an external 
Ground to Pin 1 (as shown, right).
 
 
 
3
4
5
6
2
Start of Print
Slew Label
Toggle/Pause
Reprint
Vcc
+5 VDC External Source
GPI/O A - J1
1
Ground
 
 
 
 
Seven dedicated outputs are available for control, warning, and error functions. These 
open-collector outputs are slew-limited. Optional 10K ohm pull-up resistors, tied to a 
common point for use at either +5 or +24 VDC, are available via jumper JMP 1.  
 
 
;
 
If external pull-up resistors are used (that is, without jumper JMP1 installed), 
then to avoid damage ensure that a common external voltage not exceed 
+30VDC is used. 
 
 
 
 
The table below details the GPI/O A pin assignments, settings and functions.