UI Robot Technology Co. Ltd.
M4220170607EN
Page 59
Miniature Integrated Stepper Motor Controller(
Closed-loop
)
Header
The start of a feedback message
There are 3 kinds of headers:
AA represents the ACK message, which is a repeat of the received instruction.
CC represents the status feedback, which is a description of current working status.
EE represents the error message.
Controller ID
The identification number of current controller in a CAN network (also known as Node ID)
Scope: 5 – 125.
Message ID
The property of the current message
For example, CC 05 A0 FF, where A0 denotes that there is a low level on sensor 1. For
details, please refer to following sections.
Data
Has a 7bits data structure. High is in front, and low is in the back.
In figure 12-1 and 12-2, examples are shown on how to convert a set of 7-bit data into 16-
bit data and 32-bit data.
Obviously, one 16-bit data takes three 7-bit data to represent, and one 32-bit data takes
five 7-bit data.
Terminator
The end of a feedback message. UIM motion controller utilizes “FF” or “FE” as the
terminator. If terminator is “FF”, it means there is no follow-up message; If terminator is
“FE”, it means there has follow-up messages.
Note: there are two types of feedback that has NO message ID: ACK message and Motor
Status feedback (controller’s response to FBK instruction). Other messages could have
NO data, such as some real-time change notification messages.
Figure12-1: Conversion from three 7bits message data to a 16bits data
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
16bit Binary Data
0 0 0 0 0 0 D15 D14
1
st
Byte
7
6
5
4
3
2
1
0
0 D13 D12 D11 D10 D9 D8 D7
2
nd
Byte
7
6
5
4
3
2
1
0
0 D6 D5 D4 D3 D2 D1 D0
3
rd
Byte
7
6
5
4
3
2
1
0
Data received (Hex): [XX] [XX] … [1
st
Byte] [2
nd
Byte] [3
rd
Byte] … [XX] [XX] [ FF ]
Receive sequence: earlier
later
