Ross openGear GPI-8941 Series, User Manual

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GPI-8941 Series User Guide (v9.0) GPIO Cabling • 23
GPIO Cabling
This chapter outlines the GPI input and output cabling designations for the GPI-8941.
Overview
The general purpose interface (GPI) connectors are male 37-pin DC sub-miniature connectors with 4-40
jack-screws for mating connector locking.
Inputs
There are two types of GPI inputs: isolated (dry) and pull-to-ground (wet).
• Isolated Inputs — The isolated input range is 4-30VDC, either polarity, the current is limited to 3mA. Each
input is optically isolated from the other inputs and the main card circuit. To maintain the isolation between the
external device and the card, the external device must supply the power for the inputs. If isolation is not required,
or if the external device is not able to supply the power for the input, either use the Pull-to-Ground input type or
use an external power source to 'wet' the circuit.
• Pull-to-Ground Inputs — A pull-to-ground input is activated when the path between the input + pin and the
circuit ground pin is closed. The external device closing the path must be capable of pulling 3mA to ground. The
open circuit voltage on the input + pin is 5VDC.
Outputs
The general purpose interface (GPI) outputs are Form A (SPST) relay contacts that close when the output is
activated. Each output is isolated from the other outputs and the main card circuit except when the output is
configured as Voltage source. The relay contacts are rated at a maximum as outlined in Table 7.1 on page 7-2.
There are two types of GPI outputs: contact closure (dry) and voltage source (wet).
• Contact Closure Outputs — A contact closure output provides a low resistance path between the two pins when
the output is activated, and an open circuit when the output not activated. Each output is isolated from the other
outputs and the main card circuit.
• Voltage Source Outputs — A voltage source output pr5VDC on the + pin activated, and 0V when the
output is not active. The other pin is ground.
Pinout Mapping
The rear module includes two general purpose interface (GPI) connectors (referred to as Left and Right). What
connector(s) your card requires depends on the card model.
Table 5.1 summarizes the required connector and the pins on the rear module based on the card model.
Table 5.1 Card Models
Card Model Left Connector Right Connector
GPI-8941-I16
GPI 1-16 Inputs Not Used
GPI-8941-I32
GPI 1-16 Inputs GPI 17-32 Inputs
GPI-8941-O16
GPO 1-16 Outputs Not Used
GPI-8941-O32
GPO 1-16 Outputs GPO 17-32 Outputs
GPI-8941-I16-O16
GPI 1-16 Inputs GPO 17-32 Outputs