Lenze EPM-T110 - Page 170

Transmitting parameter data
Reading a parameter (example)
10
Network via CANopen
10.5
10.5.3
l
10.5-5
EDSPM-TXXX-3.0-04/2004
10.5.3 Reading a parameter (example)
An I/O system IP20 has the node address 2. For the first module (4×analog output)
the function of the A.0 output is to be read.
Formula Information
Identifier = Basic identifier + node address
= 1536 + 2 =1538 = 602
h
• Basic identifier for parameter channel 1 (output) = 1536
• Node address of the I/O system IP20 = 2
Instruction
code:
= 40
h
• Command “Read Request” (request for reading a
parameter of the I/O system IP20)
Index = I3001
h
• Index first analog module
Subindex = 1 • Subindex = 1 (function for output A.0 among others)
Data 1
Data 2
Data 3
Data 4
Data 1 ... 4
=00
h
=00
h
=00
h
=00
h
= 00 00 00 00
h
• Read request only
11 bits 8 bytes of user data
I
d
e
n
t
i
f
i
e
r
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
602
h
40
h
01
h
30
h
1 00
h
00
h
00
h
00
h
L
0
1
L
Read Request
Read Response
Identifier = 1538
Identifier = 1410
epm-t119
Fig. 10.5-2 Reading a parameter
Formula Information
Identifier = Basic identifier + node address
= 1408 + 2
= 1410
• Basic identifier for parameter channel 1 (input) = 1408
• Node address of the I/O system IP20 = 2
Instruction
code:
= 43
h
• Command “Read Response” (response to the read
request with the current value)
Index = Index of the read request
Subindex = Subindex of the read request
Data 1
Data 2
Data 3
Data 4
Data 1 ... 4
=00
h
=00
h
=05
h
=3B
h
= 00 00 05 3B
h
• Assumption: Analog output A.0 outputs a voltage signal
0...+10Vata12bitresolution.
11 bits 8 bytes of user data
I
d
e
n
t
i
f
i
e
r
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
1410 43
h
01
h
30
h
0 00
h
00
h
05
h
3Bh
(LSB) (MSB)
Task
Telegram to the I/O system IP20
Telegram from the I/O system
IP20 (value of the requested
parameter):
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