The MASTECH or Circuit Specialist MAS345 is a handheld digital multimeter with RS232 connectivity.
It is also sold under the names Circuit Specialists CSI3451, Global Specialties Pro-70, McVoice M-345pro, Sinometer MAS345. and Velleman DVM345DI.
When it was originally sold it came with a special serial cable with one side that plugs into the meter for data logging features. I purchased this no-longer-available meter used and it came without the cable. all my searches have came up with no results.
I was hoping this forum might find someone with this cable. If they don't wish to sell it, maybe they can do a continuity test and tell me which pins go where so I can make my own from an old serial cable.

 

Here you go:

 

Thanks ModemHead,
I found the exact information elsewhere, but it was another model. So you confirmed it.
I have the header on order now (slow boat from China). I will let you know how it works out later.

 

It was a success. I finally got the serial cable was built, the USB/RS232 adapter installed, and the DAQ software running.

I am running Win-10 and nothing said it would run on this platform. So when it finally started to work, nobody was as surprised more than myself.

I came across some homemade versions that work better and one that will even export data to Excel. I might explore those avenues later, but my inexpensive home workshop is finally coming together. A cheap meter with DAQ capabilities up and running for less than $30.

Thanks again Modem Head