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| Decoding DER EE LCR Meter DE-5000 serial bitstream |
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| AlfBaz:
So, a bit annoyed by the fact that this LCR meter has serial data ouput whos bitstream can only be understood by the proprietry software, therby making it diffuclut to use in a mixed ATE environment and getting no responce from DER EE I decided to have a go at deciphering it Here's what I have so far and encorouge any and all who are into this sort of thing to add any further information they find. 17 bytes are sent per reading. Please bare in mind that the info below is what the LCR software shows as a result of me sending data that the meter may not produce B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13 B14 B15 B16 B1..0 First 2 bytes indicate start of packet and are always B0=0x00 and B1=0x0D B2 BIT7 Parrallel/Series Measurement 1 = Parallel 0 = Series BIT6 Auto 1 = Auto on 0 = Auto off BIT5 AutoLCR mode (device determines L, C or R mode) 1 = Auto LCR on 0 = Auto LCR off BIT4 SORT mode 1 = SORT on 0 = SORT off BIT3..0 NOT USED?? ALWAYS ZERO B3 BIT7..5 Frequency 0 = 100Hz 1 = 120Hz 2 = 1kHz 3 = 10kHz 4 = 100kHz BIT4 UNKNOWN always 1? BIT3 Auto Power Off (APO) 1 = OFF 0 = ON BIT2-0 NOT USED?? ALWAYS ZERO B4 USED FOR SORT? NORMALLY ZERO B5 BIT7..0 MODE 1 = Ls 2 = Cs 3 = Rs 4 = DCR B6-7 Reading B8 BIT7 When set, any changes to bits 6 to 3 (units) are ignored and the last Units are locked in BIT6..3 UNITS 0 = none 1 = ohm 2 = Kohm 3 = Mohm 4 = none 5 = uH 6 = mH 7 = H 8 = KH 9 = pF A = nF B = uF C = mF BIT2..0 Decimal point 0 = reading / 1 1 = reading / 10 2 = reading / 100 3 = reading / 1000 4 = reading / 10 000 5 = 5 digit mode? B9 BIT7..0 NOT USED?? ALWAYS ZERO B10 BIT7..4 NOT USED?? ALWAYS ZERO BIT3..0 Secondary reading mode 0 = No mode (not used?) 1 = D 2 = Q 3 = ESR 4 = Theta B11..12 Secondary reading value B13 Secondary Decimal point 0 = reading / 1 (no decimal point eg 4566) 1 = reading / 10 2 = reading / 100 3 = reading / 1000 4 = reading / 10 000 5 = reading / 1 (decimal point at end eg 4566. ) B14 UNKNOWN always shows 0x80 B15..16 Packet terminators always B15=0x0D B16=0x0A For those that are interested in snooping here's my setup Inititally I used PortMon to look at the data going from the meter to the program. The meter simply dumps 17 bytes to the Virtual Com Port. It becomes visible when you hit play in the PC application. I then decided to send my own data to PC so I could enumerate the various values You can use your own method here but a quick search gave me the following programs to use http://www.virtual-null-modem.com/download.htm Create two virtual com ports that are null-modem connected Feed data to one of the virtual ports with this http://www.aggsoft.com/com-port-emulator/download.htm and set the LCR program to listen to the other port The second program needs a text file with a line of data to send to the meter Here's an example (copied coming from the meter) #00#0D#40#58#00#02#25#D8#52#00#01#00#D6#04#80#0D#0A Simply paste the above line into a text file and then use it with the com port emulator It yields the following on the LCR's PC program Auto Cs 1KHz 96.88nF In the Grid D = 0.021 Theta value -88.7741 Q value 46.729 D value 0.0214 Z value 1642.8049 |
| Muttley Snickers:
G'Day AlfBaz, Were you using the optional USB to IR, or have you managed to find the onboard serial pin outs . Regards and Nice Work. Muttley |
| AlfBaz:
Using the IR to usb adaptor here also. It has an FTDI232RL chip in it. Simply sniffed the appropriate VCP |
| biot:
--- Quote from: AlfBaz on November 30, 2014, 10:06:00 am ---So, a bit annoyed by the fact that this LCR meter has serial data ouput whos bitstream can only be understood by the proprietry software, therby making it diffuclut to use in a mixed ATE environment and getting no responce from DER EE I decided to have a go at deciphering it --- End quote --- We've actually got a fully reverse-engineered driver for this in sigrok, so consider the job done. Unfortunately we're running behind on getting docs up for it in the wiki, but the code contains everything needed, and quite a few comments on the protocol: http://sigrok.org/gitweb/?p=libsigrok.git;a=blob;f=src/lcr/es51919.c;hb=HEAD In this case the device is based on the Cyrustek ES51919 LCR chip, and the DER EE DE-5000 driver is just a little wrapper around the code for this chip. |
| AlfBaz:
--- Quote from: biot on November 30, 2014, 03:44:47 pm ---We've actually got a fully reverse-engineered driver for this in sigrok, so consider the job done. --- End quote --- Damn it :palm: There's a day wasted. I searched and searched (including Cyrustek ES51919) and found nothing. I knew I should of asked here first PS I needed the data to drive it from labview, so thanks for the complete spec |
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