JUMO 902931 Wtrans Receiver with Wireless Data Transmission Operating Manual - Manual (Page 21)

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3 Basic principles
Each measured value can be checked for overrange and underrange by means of two limit val-
ues. The minimum and maximum measured values are saved in drag indicators.
Wireless timeout function
The measured values of the probe are monitored via a wireless timeout function. If an individual
wireless telegram is missing, the last value received is frozen. If no new wireless telegram is
received throughout the entire timeout duration, the measured value is set to "no input value"
and the top LED flashes red.
Automatic changeover of the interfaces
Both interfaces are operated via the same communication module (UART = Universal Asyn-
chronous Receiver Transmitter). If an interface cable is connected to the front setup plug, the
device interrupts communication via the RS485 (i.e. the setup connector has priority).
Analog outputs
A maximum of four analog outputs (current or voltage) are available in the device. The mea-
sured value is scaled to the set values for zero point and end value. Measured values outside
of these limits are detected as overrange or underrange. In this case, the value set here in the
parameter level (value for overrange and underrange) is applied.

Chapter 5.2 "Connection diagram", page 32
 Chapter 8 "Configuring the receiver", page 49
Relay outputs
Depending on the version, the device may have up to two relay outputs. The status that switch-
es relay output 1 or 2 is determined by different control signals. The desired control signal and
the output signal (N/C or N/O contact) for each relay can be set in the parameter level.

Chapter 5.2 "Connection diagram", page 32
 Chapter 8 "Configuring the receiver", page 49
RS485 interface
The unit is equipped with an RS485 interface with Modbus protocol to permit connection to
higher ranking systems. The baud rate, data format, minimum response time, and device ad-
dress can be set using the keypad or the setup program.

Chapter 5.2 "Connection diagram", page 32
 Chapter 8 "Configuring the receiver", page 49
Voltage supply
The voltage supply of the receiver is generated with a switch-mode PSU from the mains voltage
AC 110 to 240 V.
For the galvanic isolation of the output signals, further galvanically isolated voltages for the an-
alog and relay outputs (11.1 to 11.4), the supply for the electronics (11.5), and the interface
(11.6) are generated from the secondary voltage of the switch-mode PSU.

Chapter 5.2 "Connection diagram", page 32