Chapter 2: devicenet information, Led operation, I/o messaging – AMETEK 1990 DN DeviceNet Resolver Interface Module User Manual
Page 4: Data format
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The DeviceNet Resolver operates as a “Group
2 only slave” device. It operates as an input only
device on the DeviceNet network. All device
configurations are accomplished by using any
DeviceNet software configuration tool.
The DeviceNet Resolver is capable of
communicating at all three DeviceNet baud rates,
125K, 250K, and 500K. The node address can
be set to any address, 0 - 63. There are several
parameters: scale factor, counting direction, and
8 programmable setpoint that are configured or
modified by the user through the Parameter Object.
(See section 4.0: DeviceNet Resolver Object
Model).
2.1: LED Operation
The DeviceNet Resolver is equipped with a Network
Status LED. The network Status LED operates as
follows:
Solid Green = Allocated by Master
Flashing Green = Passed Duplicate MAC ID Test
and is awaiting to be allocated by Master
Solid Red = Fatal error. Requires user intervention.
Check for duplicate MAC ID or baud rate
communication rate setting.
2.2: I/O Messaging
The DeviceNet Resolver supports Bit-Strobe
Message Connection as well as a Polled I/O
Message connection. The DeviceNet Resolver does
not support Cyclic I/O or Change-of-State Message
Connections.
Bit Strobe Message
A bit strobed message connection is a very fast
method by which a master sends one bit (Bit Strobe
Command) out on the network and receives up to
8 bytes of data (Bit Strobe Response) from each
slave device that supports a Bit Strobe Message
Connection. The DeviceNet Resolver disregards the
command message. No user-defined configuration
is required.
Polled I/O Message
A polled message connection is used for devices
that have inputs and outputs. It can also be used for
“Input Only” devices. The master sends out a Polled
Command to each individual device and the device
responds with an 8 byte Polled Response. The
Polled message connection is not the most efficient
message connection to use for “Input Only” devices
because there is a Command message sent to and
a Response message sent from each device. This
creates a lot of unnecessary network traffic.
2.3: Data Format
The setpoint status is supplied in the first 8 bits
of the I/O message. One bit for each setpoint,
“0 = off” and “1 = on”. The next 16 bits will provide
the scaled resolver position information
(4095
maximum). And finally, the next 16 bits will provide
the RPM data
(1024 maximum). The entire I/O
message is 40 bits long. You will need to reserve 40
bits in your controller I/O image table.
Chapter 2: DeviceNet Information
Setpoint Data
Position Data
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Position Data
RPM Data
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
RPM Data
Not Used
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
Not Used
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63