Delta RMC101 User Manual
Page 665
Appendix A: Command Reference
A-13
entire polling loop by one control loop (1 or 2 ms).
Step 15 will be jumped to when an Overdrive Error occurs. It simply turns on discrete output 0,
perhaps to indicate the overflow to the operator in the form of a red light.
To summarize, the above sequence starts a move to position 4000, jumps to step 15 if an
overdrive error occurs, jumps to step 14 if the axis gets in position, and loops through steps 11-
13.
Now, compare this method of implementing a polling loop with the one used in the next example,
which is a little more difficult to follow but removes the need for the extra do-nothing step in the
polling loop (step 13 above).
Example 2:
This example offers an alternative approach to the same problem as in the previous example:
move to position 4000, detect either when the axis is in position or when an overdrive error
occurs. It is a little more difficult to follow, but removes one step from the polling loop, therefore
reducing the amount of time taken to catch any condition. Keep in mind that for many
applications, this slight gain in performance will not justify the reduction in clarity:
Step 10
Step
11
Step 12
…
Step 15
Mode
0x0081
0x0081
0x0081
0x0000
Accel
100
100
100
0
Decel
100
100
100
0
Speed
10000
10000
10000
0
Command
Value
4000
0
0
0x0001
Command
G
?
?
[
Commanded
Axes
Default
Default
Default
Default
Link Type
DelayMS
BitsON
BitsOFF
DelayMS
Link Value
0
0x1000
0x0001
0
Link Next
11
15
11
0
Step 10 starts the move to 4000, and links immediately to step 11.
Step 11 checks for the Overdrive Error bit (0x1000) of the Status word on the current axis. If this
error bit is set, control goes to step 15, otherwise control goes to step 12.
Step 12 checks the In Position bit (0x0001) of the Status word. Notice that, unlike the previous
example, the BitsOFF (b) link type is used instead of the BitsON (B) link type. Therefore, if the In
Position bit is off—that is, the axis is not yet in position—then the Link Next is taken back to step
11 and the polling continues. Otherwise, if the In Position bit is not off—that is, it is on and the
axis is in position—then control proceeds to the next step: step 13.
Step 15 will be jumped to when an Overdrive Error occurs. It simply turns on discrete output 0,
perhaps to indicate the overflow to the operator in the form of a red light.
To summarize, the above sequence starts a move to position 4000, jumps to step 15 if an