Service manual

FUNCTION OF STRING POTENTIOMETER (String-Pot)

There is a string potentiometer (string-pot) mounted on the top of each column, and connected to each

carriage, which senses the movement of the carriage. The string-pot sends an absolute analog (4-20mA) signal

to the PLC as the string is pulled in and out of the sensor. This signal is absolute, which means that the lift

will always know the height of the lift, even when powered off and on again. This signal is directly translated

into height position and can be witnessed by viewing the Post Height Screen, F2. If raising or lowering is not

possible, manually pulling the string-pot cable, while the unit is powered and pressing F2, will enable you to

see the height changes.

FUNCTION MENUS

The control screen has 10 function keys that will display various menus. They are as follows:

F1: Post ID and Active Posts Display

This screen will display the Post ID and all the active posts of the

system it is connected to.

i.e. The display to the left shows post #2 connected in a 4-post

system manner with posts #1, 2, 3, & 4.

F2: Post Height Display

This screen will display the current post height in inches.

i.e. The display to the left shows the post at a height of 42 inches.

(Note the tolerance of +/- ½ inch)