There are multiple factors to consider in desiging your system.
1) The FP-1601 requires an external power supply to power itself and the control circuitry of all the IO modules. This supply must be between 11-30 VDC and must be greater than 4.5W + 1.1(Sum of IO module power ratings).
2) The FP-DO-401's require an external power supply between 5 and 30 VDC. This supply is used to power the output channels. The power supply must have a sufficient power rating to power each of the outputs based upon the load each one will draw. Each channel outputs a voltage equivalent to the input power supply. If you need different output voltage levels, use a different power supply for each FP-DO-401.
3) The FP-AI-111 and FP-DI-301 modules do not require external power. Ex
ternal power may be routed through their V&C terminals to take advantage of the terminals and provide loop power to sensors but it is not needed.
4) It is possible to use a single power supply to power the FP-1601 and the I/O modules, however, by doing so you bypass the module to module isolation. To maintain the maximum amount of isolation, you should use one power supply per IO module that requires external power. For a small amount of isolation (I/O to control), use one power supply for the control module and one power supply for the I/O modules.
5) For modules that need to remain isolated, do not connect the V or Vsup and C or Com terminals from one I/O module to the next.
There should be several other Developer Exchange posts that also deal with this issue.
Regards,
Aaron
LabVIEW Champion, CLA, CPI
