GE Optica, Руководство оператора, Страница: 30 / 150

Installation 2-9
January 2006
Analog Outputs
Note: When the Optica is being programmed, the analog outputs
provide 4–20mA and 0–5 VDC signals representing the
designated parameters.
•
For 4–20mA output, connect to terminals labelled 4–20 (+) and
RTN (–) .
Note: The maximum load allowed for current output is 500 Ohms.
•
For 0–5 VDC output, connect to terminals labelled
0–5 (+)
and
RTN (–) .
Note:
The maximum load allowed for voltage output is 5 mA.
Example:
Assume a temperature output, scaled to range from 0°C (Tlower) to
100°C (Tupper), with a measured actual temperature of 23°C
(Tactual):
The voltage output is calculated by:
yielding an output voltage of 1.15V.
The current output is calculated by:
yielding an output current of 7.68 mA.
Vout
Tactual Tlower
–
( )
Tupper Tlower
–
( )
---------------------------------------------- 5
×
=
23 0
–
( )
100 0
–
( )
--------------------- 5
×
1.15V
=
Iout mA
( )
Tactual Tlower –
( )
Tupper Tlower
–
( )
----------------------------------------------
20 4
–
( ) ×
4 + =
23 0
–
( )
100 0 –
( )
---------------------
16
( ) ×
4 +
7.68mA
=