Input modules
Digital DC Input Modules
G4 DC input modules from the company Opto 22 are used to detect the on / off levels of DC voltage. Each module provides up to 4,000V of the optical isolation between operating inputs and logic output of the circuit. All DC input modules, with the exception of G4IDC5K and G4IDC5D, are designed with filtering on the input and with a hysteresis amplifier which enables high suppressing of the noise and high non transient "clean" switching. G4IDC5K is a fast switching module which is used in order to detect signals produced by photoconductive switches and TTL devices. Cheap G4IDC5K is used to collect data. G4IDC5MA is a special module containing a manually switch-on / manually switch-off / auto switch which is ideal for diagnostic testing of control applications. Typical applications for DC input modules include sensing the presence or absence of voltage with devices such as sensors, position switches, controllers, buttons, photoelectric switches and TTL-compatible devices. All modules contain a built in LED status indicator.
Digital AC Input Modules
G4 AC input modules from the company Opto 22 are used to detect the on / off levels of AC voltage. Each module provides up to 4,000V of the optical isolation between operating inputs and logic output of the circuit. All AC input modules are designed with filtering on the input and with a hysteresis amplifier which enables high suppressing of the noise and high non transient "clean" switching. G4IAC5MA is a special module containing a manually switch-on / manually switch-off / auto switch
which is ideal for diagnostic testing of control applications. Typical applications for AC input modules include sensing the presence or absence of voltage with devices such as sensors, position switches, floating switches, controllers, buttons, tumbler switches and thermostats. All modules contain a built in LED status indicator.
Digital Input Test Modules
G4SWIN Input Test Module from the company Opto 22 is used to simulation of the input on the inputs and outputs mounting frame. Each module contains the disconnect switch which switches off the contact on the logical side. Internal resistance limits the current by the switch and it provides a load similar to the one in a real input module. The internal circuitry for suppressing bounces of contacts allows fast obturators of switches without the false statements counts. The module G4SWIN works with a logic voltage of 5, 15 and 24 volts. Internally there is no connection to the array of inputs. Built-in LED diode indicates simulated on / off status. This module is ideal for simulation of discrete external events while testing application software.

| G4IDC5 | G4IDC5B | G4IDC5D | G4IDC5G |
| G4IDC5K | G4IDC5MA | G4IDC15 | G4IDC24 |
| G4IAC5 | G4IAC5A | G4IAC5L | G4IAC5MA |
| G4IAC15 | G4IAC15A | G4IAC24 | G4IAC24A |
| G4SWIN |
