Delta Electronics Programmable Logic Controller DVP-PLC - Manual (Page 372)

7 Application Instructions API 50-99
D V P - P L C A P P L I C AT I O N M A N U A L 7-88
3. How to set up RS-485 communication protocol in D1120
Content 0 1
b0 Data length 7 8
00: None
01: Odd
b1
b2
Parity bits
11: Even
b3
Stop bits 1 bit 2 bits
0001 (H1) : 110
0010 (H2) : 150
0011 (H3) : 300
0100 (H4) : 600
0101 (H5) : 1200
0110 (H6) : 2400
0111 (H7) : 4800
1000 (H8) : 9600
1001 (H9) : 19200
1010 (HA) : 38400
1011 (HB) : 57600 (does not support ES/SS V5.8 and below)
b4
b5
b6
b7
1100 (HC) : 115200 (does not support ES/SS V5.8 and below)
b8 Start word None D1124
b9 First end word None D1125
b10 Second end word None D1126
b15 ~ b11
Not defined
4. When RS instruction is in use, the frequently used communication format in the peripheral device will define the
start word and end word of the control string. Therefore, you can set up the start word and end word in D1124 ~
D1126 or use the start word and end word defined by the PLC. When you use M1126, M1130 and D1124 ~
D1126 to set up the start word and end word, b8 ~ b10 of D1120 have to be set as 1 to make valid the RS-485
communication protocol. See the table below for how to set up.
M1130
0 1
0
D1124: user defined
D1125: user defined
D1126: user defined D1124: H 0002
D1125: H 0003
D1126: H 0000 (no setting)
M1
12
6
1
D1124: user defined
D1125: user defined
D1126: user defined D1124: H 003A (’:’)
D1125: H 000D (CR)
D1126: H 000A (LF)
5. Example of how to set up the communication format:
Assume there is a communication format: Baud rate 9600 7, N, 2
STX : “:”
ETX1 : “CR”
ETX2 : “LF”
Check the table and obtain the communication format H788 and write it into D1120.
b15 b0
0 0 0 0 0 1 1 1 1 0 0 0 1 0 0 0
7 8 8
D1120
0
Don t care