User guide

8
PN 161-09981-007A
January 2010
Wireless I/O Extender User’s Guide
Analog Operation (Analog models only)
Requirements
•The outputs can drive 4-20 mA.
•The outputs can operate on loops with a maximum total resistance of 300 ohms.
•The input signal must be a 4-20 mA signal.
•All inputs use a common ground connection labeled “G”.
These units are bi-directional, they send and receive analog information both directions. The analog connection to the
device is made via the terminals labeled “4-20mA Input” and “4-20mA Output.” The fail state or alarm condition on loss of
communications can be set to “low (4mA)” (default) or “hold last value” for these channels independent of any other units
in the system.
In a Point-to-Point system the inputs correspond to the same numbered output on the other unit. The following diagram
illustrates the point-to-point analog example.
In a Multipoint system the analogs are assigned to a remote and incremented on the master. The following diagram illus-
trates the point-to-multipoint analog example.
Pwr
4-20mA Input
4-20mA Output
G 1 2 3 4 5 6 7 8G 1 2 3 4 5 6 7 8
Master
mA
13.7
mA
Sensor
with 4 -20 mA
Output
Note:
Loop power supply
may be needed.
The DDAA1000 units do
not supply loop power
Pwr
4-20mA Input
4-20mA Output
G 1 2 3 4 5 6 7 8G 1 2 3 4 5 6 7 8
Remote