Sd7

What does 087 mean?

An initialization error occurred at the absolute value encoder at X8, or the encoder electronics are defective. This can result from a loose cable, an open circuit, an incorrect encoder type, or failure during rotor position adjustment.

• Encoder cable disconnection: Loose connection at encoder connector (e.g., X8) or at the encoder side, causing complete signal loss.
• Open circuit in cable: One or more conductors (e.g., power, ground, data lines) in the absolute encoder cable are broken, preventing communication.
• Incorrect encoder type: An unsupported or incompatible absolute encoder type is connected to terminal X8, or the encoder selection parameter (e.g., P4-10) is set incorrectly.
• Encoder power supply issue: The encoder's internal electronics are not receiving sufficient voltage (e.g., 5V or 24V supply via X8/1 and X8/2) due to a short or fault.
• Defective encoder hardware: The absolute encoder itself has an internal electronic failure and is not transmitting valid initialization data.

Click steps to track your progress.

1. 1

   Verify all connections at terminal X8 on the device and at the absolute encoder connector, ensuring they are tight and properly seated (e.g., visual inspection for loose pins).

2. 2

   Using a multimeter, measure the resistance and continuity of each conductor in the encoder cable from X8 to the encoder, paying attention to power (e.g., +5V/24V) and data lines.

3. 3

   Measure the supply voltage delivered to the encoder via X8 (e.g., +5V or +24V between pins X8/1 and X8/2) to ensure it is stable and within specification.

4. 4

   Check the encoder type selection parameter (e.g., P4-10 or encoder initialization parameters) to ensure it matches the connected absolute encoder model.

5. 5

   If possible, swap the suspected absolute encoder with a known-good encoder of the same type to isolate whether the fault is with the encoder or the drive's input.