SSI error bit

What does F13.21 mean?

An error bit has been set in the SSI protocol by Encoder 1, indicating a data or communication problem. This can result from incorrect startup parameters, encoder settings, wiring issues, or external interference, affecting position feedback reliability.

• Mismatch between the SSI resolution (P3-55) or number of turns (P3-56) configured in the drive and the actual Encoder 1 specifications.
• Intermittent electrical noise on the SSI data or clock lines, potentially due to inductive loads or unshielded cables running parallel to power cables.
• Minor internal malfunction within Encoder 1, causing occasional setting of non-critical error bits in the SSI telegram.
• Ground loop issues affecting the SSI signal integrity, potentially caused by multiple grounding points or incorrect earthing practices.

Click steps to track your progress.

1. 1

   Cross-reference drive parameters P3-55 (SSI resolution) and P3-56 (SSI number of turns) against the Encoder 1 datasheet and adjust if necessary.

2. 2

   Visually inspect the routing of the Encoder 1 cable to ensure it is separated from high-current power cables and that shielding is continuous.

3. 3

   Capture SSI clock and data signals at drive terminal X1 using an oscilloscope to identify any transient noise or signal distortions.

4. 4

   Perform a resistance check on all SSI signal lines (CLOCK+, CLOCK-, DATA+, DATA-) and ground connection from drive terminal X1 to encoder connector.

5. 5

   Reset the Encoder 1 configuration parameters in the drive (e.g., P3-50 to default) and reconfigure carefully.