No response from instanceId xxx

[guilter]

I am getting the exception from some bacnet remote devices.
com.serotonin.bacnet4j.exception.BACnetTimeoutException: No response from instanceId 1213 at
com.serotonin.bacnet4j.util.RemoteDeviceFinder$DeviceFutureImpl.get(RemoteDeviceFinder.java:183) ~[bacnet4j-6.0.0.jar!/:?] at
com.serotonin.bacnet4j.LocalDevice$2.get(LocalDevice.java:727) ~[bacnet4j-6.0.0.jar!/:?]

Another note is that most of these I-AM packets report Maximum APDU Length Accepted of 480.

After observing, I found that when the BACnet device's max-apdu-length-accepted property value is not equal to 1476, this exception occurs. However, when the value is set to 1476, it works normally. I'm unsure how to resolve this issue and seek assistance.

[splatch]

Hello @guilter, thank you for trying Do you try to read some properties from device?

Under the hood, wrapper makes a very simple assumption of reading 3 properties at most (read property multiple), so it fits into usual defaults. Getting one more property caused my test devices fail, so I took it as a reasonable default. Having said that - the APDU length is currently not evaluated and probably that's the reason why your device fails to process requests generated by wrapper.
Out of curiosity, do you use physical device or some simulator to test?

[guilter]

Hello @splatch ,Thank you for your response. I am currently using a physical device. My issue is that I experience a timeout when reading the device, preventing me from retrieving its properties. I discovered the max-apdu-length-accepted property of the device using another software (BACnetScan, which can scan and read the device's properties). However, I am unable to read the device using bacnet4j.

[EasonKuang]

The manufacturer told me that these devices are transparently transmitted to bacnet ip through the router through bacnet mstp, which may be a problem with the router setting, but I don't know how to change it