Metex 2200P pH Analyzer/Controller - Manual (Page 21)

Model 2200P Page 19
5.9 Cycle Feature for Relays A and B
5.10.1 The 2200P has a cycling feature for the control relays. This feature if enabled will
cause the relays to cycle based on the on and off times selected. This useful
feature can help eliminate overshooting, saving expensive chemicals.
a) If you wish to have cycling control for Relay A, you must put DIP switch NO. 3
of Bank S2 in “ON” position. Similarly, if you wish to have cycling control for
Relay B, put DIP switch No. 4 of Bank S2 in “ON” position (See Section 4.7). If
either of these two switches is in “OFF” position, the corresponding Relay will
act in a simple ON-OFF manner.
b) The following example describes how to enter the ON and OFF times for Relay
A cycling control.
i) Enter the menu by pressing MENU, proceed by pressing MENU until
the CYCLE A LED illuminates.
ii) With the arrow buttons make the display read the number of seconds
(maximum 600) you wish the relay to be activated. Example 30. Press
ENTER. The display will flash until ENTER is pressed again to confirm
entry.
iii) Press MENU. The LED will flash. Now make the display read the
number of seconds (maximum 600) you wish the relay to be
deactivated. Example 60. Press ENTER. Press ENTER again as
above.
iv) With this configuration when the process reaches the Relay A Relay On
Setpoint the relay will cycle continuously 30 seconds activated, 60
seconds deactivated until the Relay Off Setpoint is passed.
NOTE: As shipped from the factory the OFF time is set at 10 seconds and the
ON time is set at 5 seconds.
x) If desired, program Relay B cycling as above, but using the cycle B
menu item.