Lenze EPM-T110 - Page 130

Transmitting parameter data
Telegram structure
9
Networking via system bus (CAN)
9.5
9.5.1
l
9.5-2
EDSPM-TXXX-3.0-04/2004
I
d
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i
f
i
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Inst
r
uction
Index
S
u
b
i
n
d
e
x
D
a
t
a
1
D
a
t
a
2
D
a
t
a
3
D
a
t
a
4
Identifie
r
I
n
s
t
r
u
c
t
i
o
n
code
LOW byte HIGH byte
Subindex Data 1 Data 2 Data 3 Data 4
The instruction code contains the command to be executed and information about
the parameter data length. It is structured as follows:
bits 7
(MSB)
bits 6 bits 5 bits 4 bits 3 bits 2 bit 1 bit 0
Command Command Specifier (cs) Length E s
Write Request 0 0 1 0
00 = 4 bytes
1 1
Write Response 0 1 1 0
0
0
4
b
y
t
e
s
01 = 3 bytes
0 0
Read Request 0 1 0 0
y
10 = 2 bytes
1
1
1
b
t
0 0
Read Response 0 1 0 0
y
11 = 1 byte
1 1
Error Response 1 0 0 0 0 0 0 0
Instruction code for parameters with 4 bytes of data length:
4bytesofdata
(32 bits)
Command hex dec Information
Write Request 23 35 Transmitting parameters to a node
Write Response 60 96 Node response to the Write Request (acknowledgement)
Read Request 40 64 Request to read a parameter from a node
Read Response 43 67 Response to the read request with the actual value
Error Response 80 128 Node reports a communication error
If an error occurs, the addressed node generates an “Error Response”.
In Data 4, this telegram always contains the value “6”, in Data 3 it contains an error
code:
Command code Error Response Data 3 Data 4 Error message
3 Access denied
80
h
5
6
Wrong subindex
8
0
h
6
6
Wrong i ndex
Instruction code
Instruction “Error Response”
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