UD78 User Guide
Issue code: 78nu2
A-4
A.2 Reading a parameter value
To read the value of a parameter, the following message is sent:
Control Address Parameter Control
EOT
GA
GA
UA
UA
M1
M2
P1
P2
ENQ
Where:
GA
= Group Address
UA
= Unit Address
M1 M2
= Menu number
P1 P2
= Parameter number
Note
No
BCC
character is sent in this message.
The Drive will reply with the following structure if the message is
understood:
Control Parameter Data Control BCC
STX M1 M2 P1 P2 D1 ... Dn ETX BCC
Where:
M1 M2
= Menu number
P1 P2
= Parameter number
D1...Dn
= Data
First character:
+
or Space for positive values
–
for negative values
BCC
= Block checksum
If a requested parameter does not exist, the Drive will reply with an
EOT
character (
ASCII
04).
Example
To read the value of parameter
1.21
in a Drive that is unit 2 of group 1, send:
Control Address Parameter Control
STX
1
1
2
2
0
1
2
1
ENQ
The Drive replies as follows:
Control Parameter Data Control BCC
STX
0
1
2
1
–
0
0
4
7
.
6
ETX
7