VMC 186/40 Motion Control Module Control Parameters
8
Status Word
The
Status Word
contains 16 bits of information about the axis. Five bits represent some type of motion error
(Lag, Lead, Overdrive, Position Overflow
, and
Parameter Error
) and can be used to trigger a halt or emergency
stop. Seven bits indicate something about the motion profile (
At Command Position, Near Command Position,
Halted, Accelerating, At Requested Speed, Decelerating
and
Stopped
) and can be used by the VME Controlled
to monitor the motion profile. Two bits can be used to monitor transducer and drive performance (Transducer
Not Responding, Value Out of Null). One bit (Parameters Initialized) can be used to make sure the VMC
186/40 has accepted control parameters, and another bit (Active) can be used to generate a periodic VME
interrupt.
Status Word Bits
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Latched
Momentary
toggle
Programmable
axis one
1 Near Command Position
0 At Command Position
2 Halted
3 Accelerating
4 At Requested Speed
5 Decelerating
6 Stopped
7 Active
8 Parameter Error
9 Position Overflow
10 Tranducer Not Responding
11 Valve Out of Null
12 Overdrive
13 Lead Error
14 Lag Error
15 Parameters Initialized
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
LSB
MSB
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
emergency
If masks
removed,
will cause
a halt or
stop
Always causes
an emergency
stop
Bit Descriptions
The
Status Word
bits 0, 1, 2, 6, 8, 9 and 11-14 are cleared whenever a 'G' command is given.
Bit 0 =
At Command Position
This bit will be set when the difference between the
Actual Position
and
Command Position
is less
than the value in the
At Command Position
field. This bit is latched and is only cleared by a 'G'
command
.
Note: This bit will not be set if the axis is halted outside the
At Command Position
window.
Bit 1 =
Near Command Position
This bit is similar to the
At Command Position
except it is set before or at the same time as the
At
Command Position
bit - never later (i.e., it has a larger window). The
Near Command Position
bit is
latched and is only cleared by a 'G' command.
