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How To: Test RFID Reader

Use this guide to verify that the RFID reader is connected and can detect RFID tags.

Step 1: Identify the RFID reader type

Reader Type Connection Used At
Zebra FX9600 TCP (IP:5084) Cargill sites (St. Clair, Sidney, Gainesville, Fullerton)
Zebra DS9908R (hybrid) USB (CoreScanner) Teasdale

Step 2: Check physical connections

For FX9600 (TCP)

  1. Check that the reader is powered on. The FX9600 has LED indicators on the front panel.
  2. Check the Ethernet cable at both ends.
  3. Check that antenna cables are securely connected to the reader.
  4. Important: Loose antenna connections are a common cause of no reads.

For DS9908R (USB)

  1. The DS9908R handles both barcode and RFID -- if barcode reading works, the USB connection is fine.
  2. RFID issues with the DS9908R are usually related to tag proximity or encoding.

Step 3: Verify network connectivity (FX9600)

  1. Open a command prompt.
  2. Ping the reader IP:
ping 10.8.15.96
  1. Expected: Replies received.
  2. Optionally, try accessing the reader web interface in a browser: http://10.8.15.96
  3. If ping fails, see Check Network Connectivity.

Step 4: Check the Diagnostics panel

  1. Open the Diagnostics panel in GateKeeper (gear icon).
  2. Find the RFID reader in the device list.
  3. Check the connection status.

Step 5: Check the RFID tag cache

The Diagnostics panel shows the RFID tag cache:

  1. Look for the tag cache display.
  2. It shows how many RFID tags are currently in the cache.
  3. Hold an RFID-tagged case near the antenna.
  4. Expected: The tag count increases and you can see the EPC of the tag.

If no tags appear

  1. Is the case close enough to the antenna? RFID range varies by antenna power and tag quality.
  2. Is the antenna connected? Check the antenna cable at the reader.
  3. Is the reader actually reading? Look for RFID diagnostic messages in the log:
  4. "[RFID-DIAG] Loop running" means the reader is actively polling.
  5. "[RFID-DIAG] TAGS FOUND" means tags were detected.
  6. "[RSSI FILTERED]" means tags were detected but filtered by signal strength.
  7. Is the RSSI threshold too strict? If you see "[RSSI FILTERED]" messages, the tags are being read but rejected because their signal is too weak. Check the RssiThreshold setting (default -127 means accept all).

Step 6: Check RFID tag expiration

RFID tags expire from the cache after a configured time (default 17 seconds). If the tag is read long before the camera trigger, it may expire before validation.

Check appsettings.json: "RFID.TagExpirationSeconds": 17

Symptoms of tag expiration: - "No matching RFID data" errors - Tags are being read (visible in cache) but not available during validation

Resolution: Increase the TagExpirationSeconds value if cases take a long time to travel from the RFID antenna to the camera.

Step 7: FX9600 antenna tuning

The FX9600 reader can be "finicky" about reading tags:

Symptom Likely Cause Resolution
Tags read too early Antenna power too high Reduce PowerLevel (default 27.0 dBm)
Tags not read at all Antenna power too low, or antenna too far Increase power or reposition antenna
Wrong tag read Reading adjacent case Increase RssiThreshold to reject weaker signals
Intermittent reads Antenna cable loose Check cable connections

Antenna configuration in appsettings.json: 

{
    "Model": "FX9600",
    "AntennaCount": 1,
    "PowerLevel": 27.0,
    "RssiThreshold": -127
}

Note: Changes to RFID configuration require an application restart.