Remote Processing RPC-2350 - Manual (Page 49)

CHAPTER 8 ANALOG I/O
8-7
Figure 8-5 Cur rent loop IC’s & connector
Current loop power
The cur rent outpu t IC' s requir e at least 12V DC to
operate . T he interna l + 12V supp ly may be used. It is
available at J12 -1. C onnect J12-1 to J12-4 and/ or -8 to
use the internal supply.
When runs are long using small gauge wire you may
need to use an externa l + 18V to + 30V D C supply to
power the curr ent loop. If this supply is also use d to
power the board, you can optionally connect current loop
input power pins CLP 0 and/or C LP1 (J12-4 and J12-8)
to J12-6. This pin also goes to P2-4.
ANALOG POWER SUPPLY
The RPC -2350 generates its own power for RS-232,
LCD display, and analog I/O. Unregulated ± voltages
are available at J7, pins 18 (+ 12V) and 20 (-12V).
+ 12V outpu t can supply ab out 45 mA . of c urre nt total.
Subtrac t 20 mA . for each 4-20 m A. output.
-12V output can supply about 15 m A. The D/ A’s use
some current (1 mA.)
COMMANDS
The following is a list of CAMBASIC com mands for
analog input an d output.
Command Function
CON FIG AIN Configures analog input for
voltage range and mode.
AIN Returns result of reading for
a channel
AOT Sends value to D/A converter
Use the table below to allocate input channels for your
application.
J7 Pin
#
Analog
input
channel
Description/ use
x n
0-5V, pressure
1 0
3 1
5 2
7 3
9 4
11 5
13 6
15 7