Gemo TT109A is a digital temperature controller with a built-in timer. It supports selectable P, PI, PD, PID and ON/OFF control and can operate with several thermocouple types or Pt100 sensors. OtomasyonAVM has been supplying Gemo products since 2013.

Standard supply: 220 VAC.
If a 24 V supply version is required, this must be specified when ordering.
Panel dimensions: 96 × 96 mm.
Output: Dry-contact relay output as standard. If an SSR output version is required, this should also be specified when ordering.

Selectable sensor inputs: J, K, T, S and R type thermocouples and Pt100.

For example, the controller can be used with a J type thermocouple or Pt100, depending on the selected input setting.

The main difference of the TT109A is that temperature control and timer operation are combined in the same unit. The built-in timer can start automatically when the process temperature reaches the selected trigger level.

ON/OFF and PID operation

If H.Hys is set to a value other than zero, the controller operates in ON/OFF mode.

If H.Hys = 0, PID control is enabled for the heating function.

Pb.C – Proportional band: Defines how many degrees before the H.SET value the time-proportional control begins. The proportional band ends at H.SET.

Ct – Control period: The control cycle period. A setting between 4 and 10 seconds is recommended in the source documentation.

Ti – Integral time: Used to compensate for the remaining difference between the process value and SET value. A lower Ti value gives a faster response, but excessively low settings may cause the process value to oscillate.

If Ti = 0, the integral part is disabled and the controller operates as P or PD.

Td – Derivative time: Helps compensate for sudden changes between the process value and SET value. Increasing Td increases the response to rapid process changes.

If Td = 0, the derivative part is disabled and the controller operates as P or PI.

PID parameter ranges

Integral time: 0–30.0 minutes; 0 = OFF.
Derivative time: 0–10.0 minutes; 0 = OFF.
Proportional band: 1–130 °C, Pb.C.
Heat hysteresis: 0–50 or 0.0–5.0 °C, H.Hys; setting H.Hys to zero selects PID operation.

The PID function also includes anti-windup and overshoot-reduction features.

Built-in timer operation

The timer start point is determined by the Process Value PV, temperature setting H.SET and trigger threshold t.HYS.

When PV ≥ (H.SET − t.HYS), the built-in timer is triggered and the countdown begins.

Once the timer has started, the countdown continues until it is reset. When the timer period is completed, the ALARM output switches ON.

Example: If H.SET = 180 °C and t.HYS = 2 °C, the timer starts when the measured process temperature reaches 178 °C or higher.

For the Pt.0 sensor setting, t.HYS can be adjusted between 1.5 and 5.0 °C. For the other sensor types, the available t.HYS range is 1–50 °C.

Timer reset

Holding the RESET button on the front panel for approximately three seconds resets the built-in timer and switches the ALARM output OFF.

Timer settings

Timer setting: 00:00–99:59 hours, t.SET.
Adjustment step: 1 minute.
Trigger setting: 1–1250 / 1.5–125.0 °C, t.HYS.
ALARM ON duration: Adjustable up to 99:59 minutes.
OUT automatic OFF: OUT can be configured to switch OFF automatically when the T.SET period has finished.

Temperature control functions

Heat SET: Lo.L to UP.L, H.SET.
Control modes: P, PI, PD, PID or ON/OFF.
Thermocouple compensation: Ambient temperature compensation.
Pt100 line compensation: Maximum 10 Ω with 3-wire Pt100.

Sensor fault protection: If the sensor or sensor wiring is open, the measurement goes outside the selected scale, or the input cannot be measured correctly, OUT operates according to the P.Err and Ct settings. If P.Err = 0, OUT remains OFF. The ALARM output remains OFF during an input fault.

Measurement ranges

J type T/C: -100 ... 600 °C, Inpt = J.
K type T/C: -100 ... 1300 °C, Inpt = K.
T type T/C: -100 ... 400 °C, Inpt = T.
S type T/C: 0 ... 1750 °C, Inpt = S.
R type T/C: 0 ... 1750 °C, Inpt = R.
Pt100: -100 ... 600 °C, Inpt = Pt.
Pt100 with decimal display: -99.9 ... 600.0 °C, Inpt = Pt.0.

Output and general features

ALARM output: Relay, NO + NC, 250 VAC / 2 A resistive load.
OUT output: Relay as standard; SSR version optional.
Parameter protection: Password-protected settings.
Memory: Program and control parameters remain stored when power is removed.

Control panel use

The TT109A can also be used in control panels containing AC drives and speed controllers.

Other temperature and process sensing products can be found in our industrial sensors section.

Gemo TT109A User Manual (PDF)

Gemo price list
Gemo contact information
Gemo main page
Industrial control devices

Installation: Sensor, supply and output wiring should be carried out by qualified technical personnel.

Before applying power, check the selected sensor type, supply voltage, terminal connections and output configuration against the product documentation.