Oxford Instruments Mercury iTC - PID Table Editor Page

Handbook
November 2011 / 59-UMC0071 / Issue 01
Mercury iTC
Page 41
USER INTERFACE
Original Instructions
 Valve Gearing
Enter a value between 0 and 7 to adjust the relationship between stepper-motor
movement and valve movement. If the entered value is x, the number of stepper-
motor steps that correspond to a valve movement from fully-closed to fully-open is
2
16
/2
x
.
For example, to set 2
16
steps for 0 to 100% valve opening, enter a value of 0, i.e.
valve steps = (2
16
/2
0
). Similarly, to set 2
14
steps for 0 to 100% valve opening, enter a
value of 2, i.e. valve steps = (2
16
/2
2
).
For a typical stepper motor / gearbox combination used on OINS systems, 2
16
steps
would correspond to 3 complete needle valve shaft revolutions, 2
15
steps would
correspond to 3/2 (1.5) complete revolutions etc. However, this may vary from
system to system.
3.2.11 PID Table Editor page
Figure 3-24 PID Table Editor page with an empty table
Figure 3-25 PID Table Editor with two rows of data
See Section 12.2.7 for an explanation of PID tables.