The Vitec Group Communications FOR-22 manual provides installation, operation, adjustment and maintenance instructions for the dual four‑wire interface board.
This manual describes the FOR-22 dual four‑wire interface board, which converts four‑wire audio signals from a Clear‑Com matrix to external devices such as cameras, intercoms, microwave and satellite links. It details the board’s functions, control panels, relay contacts, and the required chassis (IMF‑3 or IMF‑102) and connectors.
The document includes safety warnings, step‑by‑step installation procedures, wiring diagrams, adjustment of send/receive level controls, specifications, and warranty information. It is intended for qualified service personnel and system integrators who need to configure and maintain the board in a Clear‑Com system. This manual is written in Chinese.
| Audio output nominal level | 0 dBu (selectable –15 dBu or –55 dBu) |
|---|---|
| Audio output impedance | 0 dBu (600 Ω), –15 dBu (200 Ω), –55 dBu (20 Ω) |
| Frequency response (audio) | 200 Hz – 10 kHz, ±3 dB |
| Maximum audio output level | +20 dBu |
| Audio input nominal level | 0 dBu |
| Call‑signal input threshold | 4 VDC (positive or negative polarity) |
| Relay contact rating | 24 VDC, 1 A continuous (2 A peak) |
| Power‑supply voltage (PSU‑101) | ±8 VDC (unadjusted) |
| Power‑supply current (per PSU‑101) | 30 mA (no indicator), 160 mA (positive), 140 mA (negative) |
| Operating temperature range | 0 °C to 70 °C (32 °F‑150 °F) |
The board can operate in temperatures from 0 °C to 70 °C (32 °F‑150 °F).
Two 8‑pin RJ‑45 connectors connect the board to the matrix, and two DB‑9 9‑pin connectors connect to external devices.
The board can handle up to 50 V input voltage.