nvoSpaceTemp from Xenta 121 with STR-150 not displaying temps greater than 33.4 °C (92.3 °F)

Issue

nvoSpaceTemp from Xenta 121 with STR-150 stat not reading temps greater than 33.4 °C (92.3 °F)

Product Line

TAC Vista

Environment

  • Vista
  • ZBuilder
  • Xenta 121, STR-150

Cause

The STR-150 and the Xenta 100 line of controllers are capable of displaying temperatures greater than 33.4 °C (92.3 °F) or less than 8 °C (46.4 °F). However, the communication protocol between the STR-150 and the Xenta 100 is limited and thus restricts temperatures that the Xenta 100 can read from the STR-150.

Resolution

The STR-150 data sheet states that temperature range transferred to a Xenta 100 device is limited to 8 °C through 33.4 °C (46.4 °F to 92.3 °F).

If temperatures outside of that range are needed an STR-100 (simple 1.8k thermistor) or an STR-350 (communicating Lon stat with display) could be substituted. The ranges of those devices connected to a Xenta 100 device are as follows:

  • STR-100: –10 °C to +50 °C (14 °F to 122 °F)
  • STR-350: 5 °C to 45 °C (41 °F to 113 °F)