Modbus Temperature Device (Slave) Display Value different from Labview displayed Value

[JÞB]

---

@Austyno wrote:

I did increase the digit to two places but the display was still showing me one decimal place of 83.5

---

That's odd.  Oh well.  just add 0.5 to the register contents and add a #Bookmark in the code that you are adjusting for an assumed truncation of the value while the display rounds the value.  (It sounds good and the ±0.1°F is not really more than an annoyance for most issues (likely well within the devices error)

[JensG69]

---

@Austyno wrote:

using NI Modbus Library

---

OK, that library works fine with reading registers from a modbus slave. I just wanted to make sure, that your modbus API is not the reason for the differences you see.

What about part 2, did you check as many values as possible? Perhaps it's a "feature" of your instrument. Ask the supplier about that!!!

Regards, Jens

[Austyno]

Both register 1000 and 1100 have same issue of  0.1F difference. other registers do not point to process temperature. I also noticed something this morning. Sometimes, the Modbus value corresponds to display value (2% of the time), Display value more than Modbus value by 0.1F (85% of the time) and finally, Display value less than Modbus vale by 0.1F (13% of the time).

[JÞB]

Put the device in C and compare- you'll probably be able to calculate the exact ADC resolution.

[Austyno]

not sure what you mean by C. Can you explain further

[Austyno]

Sorry, was away from work. I have not done this C thing before. Can you help explain?