Publishing initial revisionTroubleshooting Cash Drawer Connectivity Issues
This article outlines troubleshooting steps for stores experiencing connectivity issues with cash drawers.
Common Problem: Retailers often encounter situations where their stores face connectivity issues with cash drawers. These problems frequently result in network errors, such as "The cash drawer did not respond to network detection request" appearing in the Associate App. This article provides straightforward troubleshooting steps to assist in resolving this issue.
Error message indicating the cash drawer did not respond to network detection request.
Solution: During each cash drawer operation, such as a sale or daily opening, the following occurs:
The App broadcasts a UDP message instructing APG cash drawers on the network to announce themselves.
The App listens for UDP broadcasts, which are the responses from each cash drawer that received the message (these responses include their ID and IP Address).
If the user scans an ID that we captured via UDP in step 2, we:
Issue TCP commands to the selected cash drawer, such as querying whether it is open or sending a command to open it.
Our experience indicates that the issue lies in step 2, where the app is not receiving UDP Broadcast responses from any drawer.
This might happen because the drawers are not receiving the app's signals, or the app is not capturing the signals from the drawers.
If the network diagnostic tools indicate no issues within the network and there is proof that the UDP Broadcasts have been sent successfully, it may be possible that the iPhones are situated on a different VLAN and are facing communication difficulties from that position.
If the issue is consistent on a specific iPhone, it may be related to permissions ("allow to interact with the local network" or similar settings in iOS).
If the issue is sporadic, it may indicate that UDP broadcasts are being dropped or filtered on the store’s router, or that the phones are switching between Access Points that may not be on the same VLAN.
This situation may require debugging with tools like Wireshark.
Verifying Network Connectivity
To effectively troubleshoot cash drawer connectivity issues, it is crucial to verify the network settings and ensure that the communication between the cash drawers and the Associate App is functioning correctly. The following steps should be taken to confirm that the UDP messages in steps 1 and 2, as well as the TCP message in step 3, are being sent and received properly.
Step 1: Check UDP Broadcasts
A network engineer should use packet capture tools, such as Wireshark, to monitor the network traffic. This will help confirm whether the UDP broadcast messages sent by the Associate App are reaching the cash drawers. If the broadcasts are not detected on the network, the issue may lie with the network router or access points, which could be filtering or blocking UDP traffic.
Step 2: Monitor Responses from Cash Drawers
Once the UDP broadcasts are confirmed to be sent, the next step is to check for responses from the cash drawers. The engineer should ensure that the cash drawers are configured correctly and are on the same network segment as the Associate App. If responses are not received, it may indicate that the cash drawers are not properly connected to the network or that there are issues with the network settings.
Step 3: Verify TCP Commands
After confirming that the UDP messages are sent and responses are received, the next step is to check the TCP commands issued to the selected cash drawer. The network engineer should verify that these commands are being sent and that the cash drawer is responding appropriately. If there are issues at this stage, it may indicate a problem with the cash drawer itself or further network configuration issues.
Network Configuration Considerations
If the network diagnostic tools indicate no issues, but the cash drawers are still not responding, consider the following:
Ensure that the iPhones running the Associate App are on the same VLAN as the cash drawers. If they are on different VLANs, broadcast traffic may not be able to reach the cash drawers.
Check the iOS local network permissions to ensure that the Associate App has the necessary permissions to interact with devices on the local network.
Investigate any potential network filtering or firewall settings that may be blocking UDP or TCP traffic between the devices.
By following these steps, retailers can effectively diagnose and resolve connectivity issues with their cash drawers, ensuring smooth operations and minimizing disruptions in the sales process.