YOKOGAWA UM33A - Using 15 V DC Loop Power Supply

10-6
IM 05P03D21-01EN
10.5 Using15VDCLoopPowerSupply
Description
The 15 V DC loop power supply is a function to supply DC power (14.5 to 18.0 V DC (21
mA DC)) to a 2-wire transmitter.
The loop power supply block is isolated from the indicator’s internal circuitry. In addition,
the block is equipped with a current limiting circuit. Therefore, accidental short-circuits
that may occur in the field do not adversely affect the rest of the indicator’s internal
circuitry.
Note that the loop power supply function cannot be used for digital communication where
the supply voltage is superposed on the signal line.
The following shows the examples of loop power supply connection to a 2-wire
transmitter.
2-wire transmitter
100 Ω
0.4-2 V DC
Indicator
SettingDetails
Parameter
symbol
Name
Display
level
Settingrange Menusymbol
RTS
Retransmission
output type of RET
EASY
OFF: Disable
PV1: PV
LPS: 15 V DC loop power supply
OUT
Parameters and Corresponding Terminals
RTS RET/OUT2 terminal