Scaling analog inputs for 0-2 ma and ±2 ma, Programming analog outputs – SATEC PM174 Manual User Manual

Page 76

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Chapter 4 PAS Application

General Meter Setup

76

Series PM174 Powermeters

zero. The device does not allow you to access this setting.

Whenever the direction of the input current is changed to
negative, the device automatically uses your full engineering
scale settings for +1 mA with a negative sign.

Scaling Analog Inputs for 0-2 mA and ±2 mA

The input scales for 0-1 mA and ±1 mA analog inputs are

always programmed for 0 mA and +1 mA regardless of the
desired input range. If you want to use the entire input range of
2 mA or ±2 mA, set the analog input scales in your device as
follows:

0-2 mA: set the 1 mA scale to 1/2 of the required full scale
output for uni-directional parameters, and set the 0 mA
scale to the negative full scale and the 1 mA scale to zero
for bi-directional parameters.

±2 mA: set the 1 mA scale to 1/2 of the required full-scale

output for both uni-directional and bi-directional
parameters.

For example, to convert voltage readings from the analog
transducer that transmits them in the range of 0 to 2 mA to the

range 0 to 120V, set the full range for the +1 mA analog input
to 60V; then the 2 mA reading is scaled to 120V.

Programming Analog Outputs

The meter can be ordered with two optional analog outputs
with options for 0-1mA, ±1mA, 0-20mA or 4-20mA output
currents.

The 0-1mA and ±1mA current outputs provide a 100%
overload, and actually output currents up to 2 mA and ±2mA

whenever the output value exceeds the engineering scale set
for the 1 mA or ±1mA.

To configure the Analog Outputs in your device, select
General Setup from the Meter Setup menu, and then click on

the Analog Outputs tab. If you are programming your device
online, analog outputs are designated as not available if they
are not present in the device.

The available analog output options are described in the
following table.

Option Range

Description

AO type

0-1mA
±1mA
0-20mA
4-20mA

The analog output type. When connected to the
meter, shows the actual AO type read from the
device. When working off-line, select the analog

output option corresponding to your meter.

Output

parameter

See Appendix B

Selects the measured parameter to be transmitted

through the analog output channel.

Zero scale

Defines the low engineering scale (in primary units)
for the analog output corresponding to a lowest
(zero) output current (0 or 4 mA)

Full scale

Defines the high engineering scale (in primary units)

for the analog output corresponding to a highest
output current (1 or 20 mA)

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