Dwyer 2600 - Manual (Page 20)

May, 2013 Page 20 of 52 949-1194 Rev. 7
Option 934, 936, Isolated Analog Retransmission.
The analog retransmission option allows the Process Variable or the Set Variable to be
sent as an analog signal to an external device. The signal may be either 0 to 10 VDC
(Option 936) or 0 (or 4) to 20 mADC (Option 934). The output may be changed in the field
from one to the other by the toggle switch located on the top printed circuit board.
Wire the output as shown on page 9.
To set up the analog retransmission, first determine the scale range that the analog signal
will represent. The maximum scale is 9999°F, 5530°C, or 9999 counts. In the Secondary
Menu set P O L for the scale value that will be represented by the low end of the analog
signal (0 Volts or 0 mA). Set P O H for the scale value that will be represented by the high
end of the analog signal (10 Volts or 20 mA).
If you require a suppressed scale or output, use the following equations to determine the
proper settings for P O L and P O H .
K = (Highest desired scale reading - Lowest desired scale reading) / (Maximum desired
analog signal - Minimum desired analog signal).
P O H = ((Maximum possible analog output - Maximum desired analog signal) * K) + Highest
desired analog reading.
P O L = Lowest desired scale reading - ((Minimum desired analog output) * K).
Next select whether you want the retransmission signal to follow the Process Variable or
the Set Variable. Usually the Process Variable is sent to recorders or other data
acquisition devices. Usually the Set Variable is sent to other controls to be used as an
analog remote set point. If you want the analog retransmission signal to follow the PV, in
the Secondary Menu set P O S r to I n P . If you want the analog retransmission signal to
follow the SV, set P O S r to S P t .
Operation is automatic. There are no further programming steps required.