Difference between revisions of "MASTECH MAS345"

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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).
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''', '''RTS low''', '''DTR high'''
See [[Multimeter_ICs#Metex_14-byte_ASCII]] for the DMM IC protocol.
* 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:
 
{| border="0" style="font-size: smaller" class="alternategrey sigroktable"
|-
!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:
 
{| border="0" style="font-size: smaller" class="alternategrey sigroktable"
|-
!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 ==
== Resources ==

Revision as of 16:49, 15 December 2012

MASTECH MAS345
Mastech mas345 device front.png
Status supported
Source code serial-dmm
Counts 4000
IEC 61010-1 CAT II
Connectivity RS232
Measurements voltage, current, resistance, capacitance, temperature, hFE, diode, continuity
Features autorange, data hold, bargraph, backlight
Website p-mastech.com

The MASTECH MAS345 is a 4000 counts, CAT II 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.

1 The software shipped by Circuit Specialists is MasView 1.1.

Hardware

Multimeter:

  • Main chip: MASTECH Japan M343-01 F0951D174 (80 pins, 16 + 16 + 24 + 24)
  • 14-stage binary counter/oscillator: ST 74HC4060 (datasheet) (marking: "ST 74HC4060 N00U732")
  • Precision perational amplifier: Texas Instruments OP07C (datasheet) (marking: "12AL9JM 0P07CP")
  • CMOS multifunctional time base circuit: Green Sea Technology GC7555AP (datasheet, English translation) (marking: "GC7555AP AA7057HS")
    • This is an NE555 compatible chip, apparently.
  • General-purpose photocoupler: Sharp PC817 (datasheet) (marking: "B > B5 PC817 Sharp")
    • "B": model = PC817X2J000F/PC817XF2J00F, ">": China factory, "B5": date code == May 1991
  • General-purpose photocoupler: Sharp PC817 (datasheet) (marking: "B > B6 PC817 Sharp")
    • "B": model = PC817X2J000F/PC817XF2J00F, ">": China factory, "B6": date code == June 1991
  • Crystal: ca. 32kHz
  • Fuse: 15A/250V (6x30mm) (for the 10A jack; interestingly the PCB silkscreen says "20A" for that jack)

RS232 cable:

Photos

Multimeter:

  • Outer package

  • Package

  • Package, open

  • Package contents

  • Device, rubber holster

  • Device, front

  • Device, back

  • Probes

  • Temperature probe

  • LCD

  • LCD w/ backlight

  • Device, open

  • Front cover

  • PCB, front

  • PCB, front, w/o LCD

  • PCB, front top

  • PCB, front middle

  • PCB, front bottom

  • PCB, back 1

  • PCB, back 2

  • LCD 1

  • LCD 2

  • RS232 connector

  • MASTECH M343-01

  • GC7555AP

  • Sharp PC817

  • ST 74HC4060

  • TI OP07C

RS232 cable:

See Device cables#MASTECH_MAS34X_cable.

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).

See Multimeter_ICs#Metex_14-byte_ASCII for the DMM IC protocol.

Resources

Retrieved from "https://sigrok.org/w/index.php?title=MASTECH_MAS345&oldid=5321"