ES238 Datasheet, PDF (27/37 Pages) Cyrustek corporation – 6000 Counts DMM / Peak

ES238
6000 Counts DMM / Peak
3.9. VAHZ Function
When voltage or current measurement mode is selected, the VAHz funtion is available. Push HZ
key to select this frequency measurement mode. The frequency is measured by auto ranging. The
maximum frequency range is 60KHz. The sensitivity of signal input is 5% full scale of signal in
voltage or current mode typically.
Configuration
RANGE
FR1
600.0Hz
FR2
6.000KHz
FR3
60.00KHz
4. Serial Data Output
The RS232 function will be activated if press down the REL key and last for 2 seconds, RS232
symbol will be shown on the LCD display. The serial data sent to SDO pin periodically at every A/D
conversion cycle by 15 times per second. The data format complies with 8Bits transmission code with
a baud rate of 9600. The host can use RS232 interface to read the data. A single data packet includes a
start bit (always 0), 8 data bits with no parity check bit, and a stop bit (always 1). The high and low
voltage levels correspond to DGND and V- respectively. SDO remains at 1 (high) when it is inactive.
Hence the start bit (0) could be used as the triggering signal to begin the reading process. The
following figure shows the data format of a single packet.
Single packet
0V
0 1 ^{D7 D6 D5 D4 D3 D2 D1 D0}
-3V
MSB
LSB
One data block consists of 17 packets. The following figure shows the format of a data block. The
Header and Device code leads the whole packets. The range packet indicates the decimal point
position on LCD panel of meter. Main_Digit1-3 consists of the readings on the LCD panel. The
function packet indicates the measurement mode of the meter. Status1-4, Unit and Bargraph give the
other status of the meter. CR and LF are delimiters used to separate the blocks.
V 2.2
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2015/12/15