Can FieldPoint be configured for use with 4 wire temperature sensors?

[LGF]

I would like to build a fieldpoint-based measurement system that is configured to accept 4 wire type low temperature sensors, pressure sensors, and several 4 wire (100ma) magnetic hall sensors.  Each 4 wire temperature and magnetic hall sensor will require a stable current source (20ma -100ma range).   We need to be able to synchronously read up to 8 sensors.  Under certain circumstances we would like update rates up to 50 Hz (0.02 seconds) on all 8 channels.  We currently have FieldPoint products, such as FP-1001 modules (RS-485 Network Interface), FP AI-110 modules (8 channel, 16 bit analog input), FP-RTD-122 modules (8 channel RTD input), FP-RLY-420 modules (SPST Relay), FP-TB-1 (36 screw terminal, Universal Terminal Base), NI-SCC-68 (68 pin Terminal Block with 4SCC expansion slots), PCI-8431 (RS-485 Serial 2 Channel Card), and other FP modules on hand that we would like to use in this experiment design if possible.  I would like more information on the NI FP-RTD-124, (4 wire, 8 ch., 16 bit RTD input module) regarding use with platinum RTDs and low level/low temperature signals, and maximum refresh rates.  Thanks for your help,

LGF    

[Matthew_Williams]

Hi LGF.  FP-RTD-124 info is here: (c)FP-RTD-124 manual.

The range of the -124 on the low end is -200C; we use it to -196C with 100 ohm Platinum sensors with good results.

The update rate, ~ 1S, however, is not going to meet your requirements. Can your temperatures really change that rapidly?

The excitation is fixed at 2mA x 135 mS with a period of 1S.  Fine for an RTD, don't know about your Hall sensors.

Your AI-110 module can be configured to read the Hall sensors with external excitation but the maximum update rate is 0.173S.

Hope that helps.

Matt