7700 MultiFrame Manual
7707IT Multi-Channel Intercom Fiber Transceiver
Revision 1.7
Page - 27
5.
GENERAL PURPOSE INPUTS AND OUTPUTS
The 7707IT provides the user with 2 General Purpose Inputs (GPI’s) and 2 General Purpose Outputs
(GPO’s). Figure 5-1 shows the input and output circuitry. Refer to sections 3.4 and 3.5 for electrical
specifications. The GPI input stage uses opto-isolators for isolation. In a typical application, providing a
contact closure or transistor connection to ground would activate the GPI inputs. The GPO output stage
uses dry contact relay closures. GPO COMMON acts as a common reference connection for both contact
closures, and accommodates closure to ground, or some other reference signal level.
Current
Limiting
(10mA)
GPI 1
GPI 2
Current
Limiting
(10mA)
In5V
GND
Frame
Ground
GPO 1
GPO 2
GPO COMMON
GPI's
GPO's
Figure 5-1: General Purpose Inputs and Outputs
