Dwyer 16L - Manual (Page 11)

December, 1998 Page 11 of 28 949-1270
THE HOME DISPLAY
The home display is the normal display while the control is operating. The
HOME display may be programmed to operate in one of three different
ways. This is controlled by the diSP menu item in the Secure Menu.
If diSP is set for Pro, the HOME display will show only the Process Variable
(the temperature, pressure, flow, RH, etc., that is being measured) on the
top display with the bottom display blank. If diSP is set for SPt, the home
display will show only the Set Variable (Set Point 1) on the top display with
the bottom display blank. If diSP is set for both, the HOME display will
indicate the Process Variable on the top display and the Set Variable on the
bottom.
If no errors or functions are active, the HOME display as programmed will
be shown.
OPERATION AND PROGRAMMING OF OPTIONS
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 7.
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 POL for the
scale value that will be represented by the low end of the analog
signal (0 Volts or 0 mA). Set POH 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, you may use the
following equations to determine the proper settings for POL and
POH.
K = (Highest desired scale reading - Lowest desired scale reading) /
(Maximum desired analog signal - Minimum desired analog signal).
POH = ((Maximum possible analog output - Maximum desired analog
signal) * K) + Highest desired analog reading.