Difference between revisions of "MASTECH MAS345"

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[[File:Mastech mas345 device front.jpg|thumb|right|MASTECH MAS345]]
The [http://web.archive.org/web/20080305031323/http://www.p-mastech.com/products/04_dm/mas345.html MASTECH MAS345] is a 3999 counts, CAT II handheld digital multimeter with RS232 connectivity.
The [http://web.archive.org/web/20080305031323/http://www.p-mastech.com/products/04_dm/mas345.html MASTECH MAS345] is a 3999 counts, CAT II handheld digital multimeter with RS232 connectivity.


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== Photos ==
== Photos ==


TODO.
<gallery>
File:Mastech mas345 package1.jpg
File:Mastech mas345 package2.jpg
File:Mastech mas345 package3.jpg
File:Mastech mas345 package contents.jpg
File:Mastech mas345 device front rubber.jpg
File:Mastech mas345 device front.jpg
File:Mastech mas345 device back.jpg
File:Mastech_mas345_probes.jpg
File:Mastech mas345 temperature sensor.jpg
File:Mastech mas345 rs232 cable.jpg
File:Mastech mas345 rs232 cable connected.jpg
File:Mastech mas345 lcd1.jpg
File:Mastech mas345 lcd2.jpg
File:Mastech mas345 device open.jpg
File:Mastech mas345 device plastic.jpg
File:Mastech mas345 pcb front1.jpg
File:Mastech mas345 pcb front displayremoved.jpg
File:Mastech mas345 pcb front2.jpg
File:Mastech mas345 pcb front3.jpg
File:Mastech mas345 pcb front4.jpg
File:Mastech mas345 pcb bottom1.jpg
File:Mastech mas345 pcb bottom2.jpg
File:Mastech mas345 display1.jpg
File:Mastech mas345 display2.jpg
File:Mastech mas345 pcb rs232 connector.jpg
File:Mastech mas345 mastech m343-01.jpg
File:Mastech mas345 gc7555ap.jpg
File:Mastech mas345 sharp pc817.jpg
File:Mastech mas345 st 74hc4060.jpg
File:Mastech mas345 texas instruments 12al9jm.jpg
</gallery>


== Protocol ==
== Protocol ==

Revision as of 00:39, 8 July 2012

MASTECH MAS345

The MASTECH MAS345 is a 3999 counts, CAT II handheld digital multimeter with RS232 connectivity.

It is also sold under the names Velleman DVM345DI, McVoice M-345pro, and Sinometer MAS345.

See MASTECH MAS345/Info for more details about the device.

Hardware

Multimeter:

  • Main chip: MASTECH Japan M343-01 F0951D174 (80 pins, 16 + 16 + 24 + 24)
  • 14-stage binary counter/oscillator: ST 74HC4060 N00U732
  • ?: Texas Instruments 12AL9JM 0P07CP
  • ?: GC7555AP AA7057HS
  • ?: Sharp B B5 PC817
  • ?: Sharp B B6 PC817
  • Crystal: ca. 32kHz
  • Fuse: 15A/250V (6x30mm) (for the 10A jack; interestingly the PCB silkscreen says "20A" for that jack)

RS232 cable:

  • TODO.

Photos

Protocol

The protocol is (partially) documented in the vendor software's "Help" window (seems to apply to MAS343, MAS344, and MAS345; the M9803R protocol is different).

  • Serial port settings: 600 baud, 7n2, DTR on
  • Every time the host sends a (any?) character to the DMM (the vendor software sends D/0x44), it returns 14 ASCII bytes containing the measurement value and so on. The documentation states that a request interval of >= 1 second is "required for stable measuring data from meter".

Packet format:

Byte(s) Description
1-2 Measuring mode (DC, AC, OH, CA, TE, DI, ...)
3 Always a space (?)
4 Sign ('-' or ' ', i.e. a minus or a space)
5-9 Decimal point and current measurement value (Examples: 10.00, 0L, 3.999)
10-13 Unit (Examples: V, mV, A, mA, kOhm, MOhm, nF, ...)
14 Carriage return (13/0x0d)

Example packets:

01 02 03 04 05 06 07 08 09 10 11 12 13 14
D C - 0 0 0 . 0 V \r
A C 0 0 . 0 0 A \r
C A 0 . 0 7 1 n F \r
O H O . L M O h m \r

Resources