Real-Time Change Notification; Rtcn Structure - UIrobot UIM2842 User Manual

Miniature Integrated Stepper Motor Controller(
UIM2842 controllers support Real-time Change Notification (RTCN). Similar to interrupter
of CPU, a RTCN is generated and sent when a user predefined event happens. The length
of a RTCN is 4 bytes. The time from the occurrence of the event to the sending of the
RTCN is less than 1 millisecond. The time is decided by baud rate. The transfer time is
less than 0.5ms when the baud rate is 115200. Then, it takes only 1.5ms from an event
happening to a RTCN being received.

4.1 RTCN Structure

The structure of an RTCN message is shown below (except event 11):
The structure of RTCN message for event 11:
CC [Controller ID] [Message ID] [Closed-loop ID] [P0] [P1] [P2] [P3] [P4] FF
Where, Closed-loop ID = 0, means open-loop control;
Closed-loop ID = 0, means open-loop control.
The RTCN system is able to response to the following events:
Table4-1: Real-time change notification events
No. Event
1
falling edge of S1
2
rising edge of S1
3
falling edge of S2
4
rising edge of S2
5
falling edge of S3
6
rising edge of S3
7
TTL output P4 low
8
TTL output P4 high
9
exceed upper limits
10
below lower limit
11
displacement control complete
12
zero position
Note:
When S1 is configured as analog, A1 denotes event 9, otherwise A1 denotes event 2.
*
When S3 is configured as analog, A5 denotes event 9, otherwise A5 denotes event 6.
** When S1 is configured as analog, A0 denotes event 10, otherwise A0 denotes event 1.
When S3 is configured as analog, A4 denotes event 10, otherwise A4 denotes event 5.
UI Robot Technology Co. Ltd.
REAL-TIME CHANGE
4.0
CC [Controller ID] [Message ID] FF
Message ID
A0
A1
A2
A3
A4
A5
A6
A7
A1/A5*
A0/A4**
A8
A9
M4220170607EN
Closed-loop
NOTIFICATION
Description
Voltage on S1: High >>>Low
Voltage on S1: Low >>>High
Voltage on S2: High >>>Low
Voltage on S2: Low >>>High
Voltage on S3 port: High >>>Low
Voltage on S3 port: Low >>>High
Voltage on P4 port: High >>>Low
Voltage on P4 port: Low >>>High
Analog input > user preset upper limit
Analog input < user preset lower limit
The desired position is reached
Position counter reaches/passes zero
)
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