Look for the Black Letter or the Numbered Resistor
By Stephen Bowen, manager of the DMP Call Center
If a Thinline Series keypad is going to support an 1108 Wireless Doorbell Module with a Westminster chime, the DMP Technical Update-0952 says you need “Level J” hardware. What is “Level J” hardware you ask? Great question! On the circuit board of DMP hardware, you will either see a handwritten letter or a resistor chip near a square that says “LEV” to identify the hardware level.
Anything that requires a letter level requires that letter or higher. Additionally, once a circuit board has been set up for resistors, letters will no longer be used. This means a resistor level is always higher than any letter level for that particular circuit board.
All resistors will have a number on them. For instance, the previously mentioned technical update says “Level J” is required. If there is a resistor it is automatically newer than the letter. If the resistor says 101 it exceeds the Level J requirement and therefore supports the new feature.