ES51977
3 3/4 AUTO EASY
(4) Serial Data Output
The serial data is output two times from SDO pin on each A/D conversion cycle.The
data format satisfy JIS 7BIT transmission code and the baud rate is 2400,it means the
receiver terminal can use RS-232 interface to read data .
single package
0V
p
D0 ~D6
MSB
0
P 1
-3V
LSB
A single package include a start bit(0),D0~D6(7 bit), a parity check bit(odd) and a
stop bit(1). All the data stream is consist of 110× 2 bits. The high and low voltage levels
corresopnd 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 begain the reading process.
all package
p
p
p
0
1 0
1 0
1
range
digit1
status
digit3
digit2
p
p
p
p
p
p
0
0
1 0
1 0
1 0
1 0
1
1
digit0
function
option2
option1
p
p
0
1 0
1
CR
LF
Digit0 ~ 3 data is exactly the receiver display number,but the status, function,range,
option1,option2 data all need written program to judge what the data mean.
Note : LSB bit is sent first,then MSB bit.
The meter always output the current input value to the serial port in spite of HOLD
mode. Each block is repeated twice in one conversion cycle. The detailed data format of
each packet is listed below.
13
92年8月4日
CYRUSTEK [ Cyrustek corporation ]
