The OMB-DBK5 current-output
card provides OMB-DAQBOARD-2000
Series data acquisition
systems with the ability to control
four isolated 4 to 20 mA current
loops. The OMB-DBK5 acts as a
current loop transmitter by
modulating current from an external
source. The OMB-DBK5 can be
programmed with a static value
whenever the data acquisition
system is not transferring A/D data.
As many as sixty-four OMB-DBK5’s
can be used in one system, to
obtain up to 256 outputs.
Each of the OMB-DBK5’s channels
contains a 12-bit D/A converter to
set the loop current. All channels
are optically isolated from the data
acquisition system and from one
another by 500 V.
The OMB-DBK5 is compatible with
regulated or unregulated loop
supplies of 12 to 45 Vdc. It also
provides compliance with loop
resistances of up to 1950 ohms,
depending on the source magnitude.
Current Loop-Powered Outputs
Since the isolated outputs of the
OMB-DBK5 are loop powered, the
card maintains control of the loop
current even when the data
acquisition system is powered down.
When loop power is first applied, the
OMB-DBK5’s outputs assume their
4 mA default state. If at any time the
data acquisition system’s power is
lost or communication with the data
acquisition system fails, the
OMB-DBK5’s outputs retain their
last set values.
DB37 male, mates with P1
pinout on OMB-DAQBOARD-2000
Series; screw terminals for signal
0.1% full scale Resolution:
4 µA/LSB, monotonic Isolation: 500 V Voltage Range:V loop = 12 to 45 V Compliance: R loop = (V loop - 6) / 0.020 Example Voltage
@ Vexc = 35 V; MDR* = 1450 Ohms
@ Vexc = 15 V; MDR* = 450 Ohms
* MDR (maximum drive resistance) Cables: Use OMB-CA-37-x with
† All dollar amounts on this site are shown in US currency.
Keywords:4-Channel Current Output Card for OMB-DAQBOARD-2000 Series