Difference between revisions of "MASTECH MAS345"
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== Protocol == | == Protocol == | ||
The protocol is 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''' | * Serial port settings: '''600''' baud, '''7n2''', '''DTR on''' | ||
* Every time the host sends any character to the DMM, 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". | * 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". | ||
* Example packets: '''DC -000.0 V\r''', '''AC 00.00 A\r''', '''CA 0.071 nF\r''' | |||
{| border="0" style="font-size: smaller" class="alternategrey sortable sigroktable" | {| border="0" style="font-size: smaller" class="alternategrey sortable sigroktable" | ||
| Line 44: | Line 45: | ||
|- | |- | ||
| 1-2 | | 1-2 | ||
| Measuring mode | | '''Measuring mode''' ('''DC''', '''AC''', '''OH''', '''CA''', '''TE''', ...) | ||
|- | |||
| 3 | |||
| '''Always a space''' (?) | |||
|- | |- | ||
| 4 | | 4 | ||
| Sign | | '''Sign''' (''''-'''' or ' ', i.e. a minus or a space) | ||
|- | |- | ||
| 5-9 | | 5-9 | ||
| Decimal point and current measurement value | | '''Decimal point and current measurement value''' (Examples: '''10.00''', '''0L''', '''3.999''') | ||
|- | |- | ||
| 10-13 | | 10-13 | ||
| Unit | | '''Unit''' (Examples: '''V''', mV, '''A''', '''mA''', '''kOhm''', '''MOhm''', '''nF''', ...) | ||
|- | |- | ||
| 14 | | 14 | ||
| Carriage return | | '''Carriage return''' ('''13'''/'''0x0d''') | ||
|} | |} | ||
Revision as of 00:19, 7 July 2012
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.
Manual: Original version (2008), German version from ELV (2002)
Software: "DMM VIEW" version 2.0 (from ELV; for Win98/NT/ME/2000/XP; supports MAS343, MAS344, MAS345, M9803R)
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)
- ?: 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
TODO.
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".
- Example packets: DC -000.0 V\r, AC 00.00 A\r, CA 0.071 nF\r
| Byte(s) | Description |
|---|---|
| 1-2 | Measuring mode (DC, AC, OH, CA, TE, ...) |
| 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) |
Resources
TODO.