MST – Motor Status Acquisition Command
A read-only command that returns axis status, including error statuses such as end limit stop, alarm stop, and EMG stop.
Applies to: CMD-4CR, CMD-4EX-SA, CMD-2ED-SA, CMD-2EX-SA
Note: The MST command was 20-bit (bits 0-19) for Commander Version V1xx and V2xx. MST was expanded to 21-bit (bits 0-20) in Version V3xx. Bit 20 is valid for firmware version V301 and later version. Older versions will always return a 0 at bit 20.
ASCII/Standalone MST[axis]
Syntax
Read
MST[axis]
|
Where: [axis] is set to X, Y, Z, U, to specify the axis to acquire the status of. |
Reply
Command is accepted and executed
Applies to: CMD-4CR, CMD-4EX-SA
Read
The reply returns a 20-bit integer with the following bit structure:
|
Bit |
Command/Function |
Condition |
|
|
0 |
Accelerating |
0: Not accelerating |
1: accelerating |
|
1 |
Decelerating |
0: Not decelerating |
1: decelerating |
|
2 |
Constant Speed |
0: Not at constant speed |
1: At constant speed |
|
3 |
Alarm Signal Input Status |
0: OFF |
1: ON |
|
4 |
Positive End Limit Status |
0: OFF |
1: ON |
|
5 |
Negative End Limit Status |
0: OFF |
1: ON |
|
6 |
Home or Origin Status |
0: OFF |
1: ON |
|
7 |
Slow Down Input Status |
0: OFF |
1: ON |
|
8 |
Positive End Limit Error* |
0: No Error |
1: Error |
|
9 |
Negative End Limit Error* |
0: No Error |
1: Error |
|
10 |
Alarm Error* |
0: No Error |
1: Error |
|
11 |
In-Position Input Status |
0: OFF |
1: ON |
|
12 |
Deviation Counter Clear |
0: OFF |
1: ON |
|
13 |
Z-index Input Status |
0: OFF |
1: ON |
|
14 |
External Start Input |
0: OFF |
1: ON |
|
15 |
0: OFF |
1: ON |
|
|
16 |
EMG Error Status* |
0: No Error |
1: Error |
|
17 |
Stop by Slow Down Detection** |
0: Not Stopped |
1: Stopped |
|
18 |
Wait for In-Position Input Status |
0: Not Waiting |
1: Wait |
|
19 |
Wait for External Start Signal Input |
0: Not Waiting |
1: Wait |
|
20 |
External Stop Input |
0: OFF |
1: ON |
* For Bits 8, 9, 10, and 16, errors must be canceled with the CLR command before next operation.
** For Bit 17, additional operations can be performed with flag ON, but flag will remain ON until canceled by CLR command.
Command cannot be processed
An error message is returned. See Error Codes
Example
Read MSTX * returns the status of X-axis
Reply decoding examples * reply examples based on the CMD-4CR
Reply 64 * Returns 64 after motor at home limit, or 0000 0000 0000 0100 0000, bit 6 indicates unit is in home position limit is on.
3080 * Returns 3080 for X-axis with alarm on and alarm error message. Equivalent in binary is 0000 0000 1100 0000 1000.
Bits 3, 10, and 11 are on. This indicates alarm input is on, alarm error is on,
and motor in position limit is on.
Notes
An online Excel calculator to decode the MST reply for the Commander series is available here.