Faster RS232 communication with fluke 8846a for measurement

[manvi]

I’m using Fluke 8846A for measuring current in a setup where the current range is set to 10A. I’m using MEASure method to read value from Fluke 8846a using RS232 communication at baud rate of 115200 with one stop bit and no parity in remote mode. The time taken from the query to receiving the response is roughly 275ms which is a bit high for my application. I would ideally want it to be less than or equal to 50ms. Is there a way to make this communication faster?
Also I’m trying to synchronize this reading from another source so I want to collect data by single trigger which I think MEASure method provides.

Code snippet used for profiling:

query_msg = "MEAS:volt:dc? 10\r"
ser.write(query_msg)
# Receive data until   
print(time())
received_data = ser.read(17)
print(time()) 


Time printed(s) in terminal:
1717717621.2261405
1717717621.5009155

[NiHaoMike]

I haven't worked with that particular meter but does it have a "streaming" mode where it gets set once and then just sends each reading to the PC?

[rcjoy]

The 8846A Programmers Manual gives several recommeded settings for fast measurements.

See the section titled "Optimizing System Speed for I/O Operation" on page 3.

[Gertjan]

Hi Manvi,

Are you using a low resolution setting on your 8846A? (For example 4,5 digits or 0.02NPLC) When using high resolution the meter needs a longer integration time. (100NPLC = 100 power line cycles = 2 seconds integration time @ 50Hz mains)

See the 8846A specifications:


4486A-measurements-rates-1000pix.png

So when set to 4.5 digits / 0.02NPLC the meter should be plenty fast for your application. When you need more resolution 5.5digits / 0.2NPLC might work too. It is a balance between resolution and speed really....

See note 1 for more suggestions for speed improvement (display off, auto range off, math off)

Also see note 4: Your RS-232 speed of 115200baud is mentioned as having a maximum measurement speed of 711 measurements per second. So that should not be a limitation too.

Regards, Gertjan.