How do I read a device's analogue value?
Fit the sensor to the TCH-B200, switch it on with the left key, then press the centre key to display the analogue value.
Direct answer
Fit the sensor to the TCH-B200 hand-held programmer, press the left key to switch it on, wait for the address to appear, then press the centre key. The display shows A, for analogue value, followed by the sensor's analogue reading, which is updated continuously for up to 3 minutes or until you press the right key to switch the programmer off.
Applies to
- Products / Models: TCH-B200. Reads the analogue value of the ESP sensor range: ALN, ATJ, ACB, ACC and ACD. Most sensors clip directly onto the programmer. An ACB-EW is connected through a PL-2 programming lead instead, as described in Can I address mini-modules and call points?
- Firmware / Version: Not applicable
- Region: UK / Europe
- Standards: Not applicable
Steps
- Clip the sensor onto the programmer, lining the three locating tabs up with the grooves. An ACB-EW does not clip on: connect it with a PL-2 programming lead.
- Press the left key to switch the programmer on and wait for the sensor address to be displayed.
- Press the centre key. An A is displayed, followed by the analogue value.
- Press the right key to switch the programmer off when you have finished.
Interpreting the value
A sensor becomes contaminated over time, so the point of the reading is to confirm that the value still falls within the normal operating range. The ranges are published in Application Note AP047 and are control panel dependent.
As a guide, a photoelectric smoke sensor or multi-sensor in the ALN, ACC or ACD family reads a zero point of about 61 when new, with a fire point of about 193. On a heat sensor the analogue value tracks the temperature at the sensor, so there is no fixed range to compare against; Application Note AP047 gives the formula for converting the displayed value into degrees Celsius. These figures are typical values from new and depend on the control panel in use, so treat the panel's own maintenance thresholds as authoritative.
AP047 also gives the maintenance fault bands for the photoelectric smoke and multi-sensors it covers, the ALN-EN, ALN-ENM, ACC-EN and ACC-ENM: 29–35, 88–94, 155–161 and 226–232. A reading that falls in one of those bands is what indicates a maintenance fault. Those bands cover the models listed above, so for an ATJ heat sensor or an ACD multi-sensor treat the panel's own maintenance thresholds as authoritative. Whether a maintenance fault is reported at all is a control panel option.
Two limits are worth knowing. The programmer reads the zero point of the sensor only. And a value outside the normal range does not necessarily mean the sensor is faulty: it usually means the sensor needs cleaning, and possibly re-calibration.
How-to video
The video below shows a sensor's analogue value being read on the TCH-B200.
When to contact technical support
Contact Hochiki Europe technical support if the programmer shows E6 during an analogue level reading — see What do the TCH-B200 error codes mean? — if a sensor stays outside its normal operating range after cleaning, or if you need to confirm the correct range for a particular sensor model.
Safety note
This article is general guidance for Hochiki Europe products. Design, installation, commissioning, maintenance and modification of fire detection and alarm systems should be carried out by, or under the responsibility of, a competent person in accordance with the applicable standards (for example BS 5839-1 in the UK). Statutory requirements imposed by the relevant enforcing authority also apply. Always refer to the current product manual and data sheet for the exact model before carrying out any work.
References
Last reviewed: 2026-10-23 — Reviewed by: Hochiki Europe Technical Support