METRIX MX57EX

[lionelkjh]

Hello everyone! I have a high-end Metrix mx57ex, and I also have calibration software. I do not have the link of the multimeter to the computer. I have in my possession an eeprom programmer (TL-866CS) and I was able to extract the memory (93C46). So my question is: is there a way to read from the Metrix calibration software the contents of the eeprom memory (bin file), to correct some errors in calibrating the multimeter on the 'computer? Thanks in advance for your help in this headache that I try to elucidate .....

[lionelkjh]

sniff!

[2N3055]

My advice would be to buy/make a cable and not tamper with the imstrument...if you have cal software..

[lionelkjh]

Hello; thank you for your reply. How to make the cable (The original cable can not be found) ......

[macboy]

The cable is simple to make. Refer to my old post at https://www.eevblog.com/forum/testgear/metrix-mx56c-bk-precision-5390-multimeter-teardown/msg268678/#msg268678

You need a USB UART converter ($1 to $2 on ebay etc.), plus a IR LED, an IR phototransistor, and a couple resistors. You wire the IR LED to the transmit side of the USB UART - use a series resistor of about 1k and wire the cathode to the Tx pin and anode to the +3.3 V pin. You connect the phototransistor to pull the Rx pin low when receiving (use a pull up resistor also). If you point your LED at your phototransistor, you should receive whatever you transmit on the serial line using a terminal program like putty or hyperterminal. If you block the light path, it should stop echoing. After that works you can try to talk to the meter. The simplest thing to do is press PRINT key to get a reading as ASCII text over the serial link (open the port at 2400/8/N/1). After that works you can try the software.

[lionelkjh]

Good evening: thank you for this precise answer! A question still crosses my mind: Is there a universal software for all multimeters to calibrate (with the interface you mention), and how to get it