User Manual

Page 13
activation switch with the digital input options detailed in the installer menu. (see page 17).
Simply place a momentary volt free switch across “DI” and Com “0-V” terminals to activate the
doorbell. Once pressed, the doorbell will chime for about 10 seconds.
Outside Door Station
When coupled with the optional Smart
Temp door station the guest can set the
room as “Do Not Disturb”, call for
housekeeping or be alerted to visiting guests
with a pleasant doorbell chime. Hotel staff
are informed about the room status or
guest’s needs by text information displayed
on the door station LCD or the door station
backlight colours.
Connection between the SMT-131 and the hotel door station is cable fitted with RJ12 plugs.
Cables can be provided at additional cost at up to 15 metres maximum. Alternatively, custom
cables can be produced. They are direct wired (not cross over).
When fitting the door station, the SMT-131 DIP Sw8 must be ON. The outside door station will
flash all LCD segments if DIP Sw8 is in the wrong position.
Automatic Day Set Temperature
The SMT-131 can optionally reset the user set point and replace with an installer defined set
point after the SMT-131 has been off for more than 6 hours. This will typically happen after one
guest has checked and before the next guest checks in but will not generally affect a guest who
may turn the thermostat off for a few hours or so or who may go out for the afternoon.
Option 40 in the installer menu defines this Function. Off or a value between 15 and 30c or 59-
86F
Modbus Wiring
Modbus communications unlock many additional functions within the SMT-131 thermostat. It
also permits all modes, functions and controls to be remotely supervised and adjusted from a
central location if needed. Modbus object data can be found on page 15 of this manual.
The SMT-131 uses a high-powered Maxim chipset that will “theoretically” permit the connection
of up to 255 devices on a single Modbus node. RF noises and other interferences will reduce the
real world permitted connections to a maximum of 150 ~ 200 in most cases.
Modbus and other communication protocol rely on the quality of cable and good installation
practises to ensure reliable communications. Modbus requires the use of screen cable with the
drain grounded in a single location.
When using a common power supply or when using a modbus master that also powers the SMT-
131, ensure the R (24v active), C (24v common) Data A & B wires are not crossed.
Hint! When the SMT-131 is connected to a working Modbus Network and receiving valid data,
the decimal point in the temperature display will blink. If there
is no communication or the SMT-131 is receiving corrupted
data, this decimal point will remain on steady.