If Err.255 appears when programming or verifying a module, this can have various causes:
First of all check whether the serial number has been typed correctly as shown on the sticker on the module or on the box. A serial number always consists of 6 digits or 10 hexadecimal characters (eg 0006B01ADE), the first 4 of which determine the module type.
Perform a test via "Utilities / Communication Check". Enter the last 6 digits of the serial number here and click on “Start Module Test”. With perfect communication with this module you have to see a nice flat line at 100%. If you see a flat low line, then there is never communication. If the line is pulsed, then there is poor communication. Then check whether the bus voltage (+/- 14V) is still correctly applied to the module or check the cabling. Try communicating with the module directly to the controller with 2 short bus wires (without any other connected modules) before sending it back via our RMA procedure.
A number of modules can send out their serial number: