Issues Migrating from USB-1408FS to USB-1408FS-PLUS

[NThornstrong]

Hello, 

We are having issues with our circuit after switching to the 1408-PLUS over the 1408 (using single ended mode). It is a legacy circuit and had no issues with the 1408, though it does look like we were exceeding the 10v input limit (12V applied). The circuit we are measuring triggers a circuit breaker when using the 1408 PLUS, the 1408 was fine and the circuit functioned as intended. All other boards within the circuit have been swapped and tested, all cables checked, and all input voltages to the circuit confirmed within spec. Does anyone know if the issue could arise from increased sensitivity to input overvoltage in the 1408 Plus? Is there a standard config change we need to make so the PLUS matches the function of the 1408 standard? Thank you for the help in advance. 

[Fausto]

Hello @NThornstrong.

The MCC USB-1408FS-Plus cannot be modified to match the USB-1408FS.  Both devices have an absolute maximum input voltage specification of +/-28 V max.  Are you able to test the analog input channels in differential mode instead?  Does that help?

USB-1408FS User's Guide:  https://www.mccdaq.com/pdfs/manuals/USB-1408FS.pdf

USB-1408FS-Plus User's Guide:  https://www.mccdaq.com/pdfs/manuals/USB-1408FS-Plus.pdf

 

Regards,

Fausto

 

[NThornstrong]

Hello Fausto and thank you for the response, 

by absolute max are we talking the applied voltage on all Analog inputs at any given time? We are unable to test the analog inputs in differential mode without rewiring our machines and changing software to my knowledge. Is there an MCC product that will function the same as the 1408FS that we may purchase in its stead? Thank you. 

[Fausto]

Hello @NThornstrong.

The absolute maximum input voltage specification is per channel and for an instantaneous amount of time, not a long period.  The USB-1408FS-Plus is the replacement for a USB-1408FS.  There are other MCC devices available, but you need to identify the actual issue with your application. 

Can you describe your circuit and all the connections?

Do you have another USB-1408FS-Plus to confirm the behavior?

Regards,

Fausto

[NThornstrong]

Hello Fausto, 

We have tried another FS-PLUS and had the same issue. Though one of the FS-PLUS also developed a firmware issue. I noticed there is no download for the 1408FS-PLUS firmware on the MCC website. Is it possible to get a hex file for this or are we left with a bricked 1408FS-PLUS now? Thank you. 

[Fausto]

Unfortunately, a hex file to update the firmware is not available for field updates, nor are these modules serviceable by us.  As I mentioned previously, both devices have an absolute maximum input voltage specification of +/-28 V max, for an instantaneous amount of time.  Test one of your output signal with the module's input channel configured in differential mode.