Danfoss VLT MICRO Manual page 89

1 Computer Control
• There is a built-in RS-485 serial interface, marked (RJ-11Jack) on the control
block. The pins are defined below:
Each VLT MICRO drive has a pre-assigned communication address specified by
Pr.88. The computer then controls each AC drive according to its communication
address.
• The VLT MICRO can be setup to communicate on Modbus networks using one of the
following modes: ASCII (American Standard Code for Information Interchange)
RTU .
Users can select the desired mode along with the serial port communication
protocol in Pr.92 and
• Code Meaning:
ASCII mode:
Each 8-bit data is the combination of two ASCII characters. For example, a 1-byte
data: 64 Hex, shown as "64" in ASCII, consists of "6" (36Hex) and "4" (34Hex).
Character "0"
ASCII code 30H
Character "8"
ASCII code 38H
RTU mode:
Each 8-bit data is the combination of two 4-bit hexadecimal characters. For example,
64 Hex.
2 Data Format
2.1 10-bit character frame (For 7-bit character):
• (7, N, 2: Pr.92 = 0)
Start 0
bit
2: GND
3: SG–
4: SG+
5: +5V
6 1
Pr.113.
"1" "2"
31H 32H
"9" "A"
39H 41H
1 2 3
7-bit character
10-bit character frame
89
VLT
"3" "4" "5"
33H 34H 35H
"B" "C" "D"
42H 43H 44H
4 5 6 Stop
® ® ® ® ®
MICRO
terminal
or
"6" "7"
36H 37H
"E" "F"
45H 46H
Stop
bit bit