9752 Installation Guide
3. Installation
497098 Issue 3
Page 15
It is possible to extend the keypad cable run by using additional power
supplies, but only up to the recommended maximum of 200m.
When carrying out the cabling, there are two important points to remember:
1. Do not connect anything other than keypads, expanders and a single
keyswitch interface to the bus. The keypad bus power supply is limited to a
maximum of 400mA.
2. Check between 0V and 12V on the keypad bus at the point furthest from
the control unit: the voltage must be at least 12.0VDC when all the keypad
backlights are on.
Note: The following instructions assume that you have already run all the
necessary cabling.