TekPower TP4000ZC
The TekPower TP4000ZC is a 4000 counts, CAT II (600V) handheld digital multimeter with RS232 connectivity.
This multimeter appears to be a rebadged Digitek DT4000ZC.
Hardware
- Multimeter IC: The microcontroller is an unidentifiable plastic blob. Based on the communication protocol, the chip seems to be a Fortune Semiconductor FS9721
- LM358 opamp
- HEF4013BT flip-flop
The RS-232 connector is a standard 3.5m stereo jack, with the ring left unconnected. The transmitter is optically insulated from the rest of the device. The DB-9 connector has a loopback resistor between the RX and TX pins.
Photos
Protocol
See Fortune Semiconductor FS9721#Protocol.
- User bit 2 is used to indicate temperature measurement in degrees Celsius.
Segment lettering
C | ||
B | G | |
F | ||
A | E | |
D |