Check is now critical: check=device-modbus

In Consul logs ,it shows "Check is now critical: check=device-modbus"

Start with the Consul log entry showing "Check is now critical: check=device-modbus" and reproduce the check failure in the device-modbus service. No source file or test is named, so trace how the device-modbus check is registered and determine the failure condition. Done means the cause is identified and the check no longer becomes critical under the reported conditions.

Written by the indexing model from the issue text.