The S4T-770-S puts a tone sounder inside the optical-and-heat Self-Test head. It uses three analogue channels — 1 forward optical, 2 heat, and 5, the channel that reports sounder, VAD and speech faults back to the panel — and its plate declares EN 54-3, 5, 7, 17 and 18.
Channel 5 is the working difference from the silent S4T-710: a failed sounder is raised as its own fault at the panel instead of being found at the next service visit. The baffle ring is white, which on this range identifies a head with sound functionality.
Tone output only — there is no stored speech on this part. For voice on a dual-angle sensing block, see S4T-711-V; for the identical audible output on a heat-only block, S4T-780-S.
Technical data
| Sensing elements | Forward-scatter optical smoke sensor and heat sensor |
| Label marking | OH/S |
| Analogue channels | 1 optical (forward), 2 heat, 5 alarm faults |
| EN 54 parts declared | EN 54-3, 5, 7, 17, 18 |
| Sounder current | 2 mA average; 4.5 mA maximum in Turbo mode |
| Baseline at manufacture (Tnew) | Channel 1 optical 25; channel 2 heat 66 |
| Baffle ring | White |
Specifications from Gent 4188-1130 issue 1 (12/23).
Compatibility
Fits the S4-700 base with the S4-705 IP21C plate. Self-Test needs the Vigilon loop of a Vigilon plus or Compact plus panel on compatible firmware.
Installation
Set the volume at commissioning, remembering that the level must not go below 65 dBA at 1 m for standards compliance — the system will not allow it down to zero. Turbo mode buys a further 3 dB but is the higher-current condition, so decide it before the loop load is signed off rather than after.
Full details: S-Quad Self-Test (S4T) Data and Installation — 4188-1130 · 28 pages · technical data, sounder output and tone information, and the analogue channel map
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