Chapter 3
Signal Connections
©
National Instruments Corporation
3-5
Current Output for the 6704
You can connect a floating or grounded load to your 6704 device at the
current output channel. You do not need an external floating power supply
to complete the controlled current loop. You can control the current loop
from 0.1 to 20.2 mA. The compliance for the current loop is 0 V to
10 VDC.
Warning
Because 6704 devices are not electrically isolated from high voltages, a load
with high common-mode voltages can damage the 6704 devices. National Instruments is
NOT
liable for any damages resulting from any such signal connections.
Figure 3-3 shows how to connect a current channel (ICH) as a current
output.
Figure 3-3.
ICH Connection as a Current Output
Because each current channel shares a ground line with a voltage channel,
you should try to minimize the effect of the return current from your current
channel on the voltage that you are outputting on your voltage channel. For
example, if you output 20 mA on a current channel and return that current
to the 6704 device along the shared ground line in a cable with an
impedance of 0.1
Ω
, you will see a 2 mV drop in the voltage output by the
AGND
ICH
PCI/PXI-6704
Load
0.1 to 20.2 mA
