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Chapter 3
3.1.2 Jumper JP5 Setting for the Reset State
Jumper JP5 gives the PCI-1720U a new and valuable capability. With
JP5 enabled, the PCI-1720U “memorizes” all D/A output settings and
output values, and, in the event of a “hot” reset, i.e., the power is not shut
off, the settings and output values present at each channel just prior to
reset are still maintained. This feature is very useful for field applica-
tions. For example, it may allow a computer be “hot” reset without
requiring the whole control system to shutdown. (Since output values are
left unchanged.)
Complete loss of power to the card clears all settings and output values
even if JP5 is enabled; i.e. if the power to the card is disconnected, the
card’s initial power-on state will be the default state. The default state is
the output range for all channels is 0~5V and all the output values are 0V.
When jumper JP5 is disabled, power-off or “hot” reset results in outputs
returning to their default state.
Figure 3.3: Jumper JP5 Setting for the Reset State
Note!
In order to maintain accurate outputs for your
field applications, it is important that you calibrate
the PCI-1720U’s variable resistors (VRs) from
time to time. Calibration instructions are pro-
vided in Appendix A.
JP5
Keeps last status after reset
Loads default while reset
