GW-7557 PROFIBUS/HART Gateway User Manual (Version 1.00, Dec/2011) PAGE: 726. TroubleshootingThe troubleshooting list can help users to resolve the problems when using the GW-7557. If the problem still can't be solved, please contact with technical staff of ICPDAS.Table 12 Errors and solutionsItem Trouble state Solution1'PWR' LED indication ofthe GW-7557 is alwaysturned offThe power supply of GW-7557 has some problems. Please checkthe wire connection of the power and the voltage is between10~30VDC .2'ERR' LED indication of theGW-7557 is always turnedonThat means the GW-7557 isn't connecting to the PROFIBUSMaster station. Please check the wire connection and thePROFIBUS Master station. The configuration and address ofGW-7557 in the PROFIBUS Master station are not correct.3 'ERR' LED indication of theGW-7557 is flashing fastIt means the GW-7557 connects with Utility.4 'ERR' LED indication of theGW-7557 is flashing slowIt means the GW-7557 has diagnostic messages. Please checkdiagnostic messages in the PROFIBUS Master station.5PROFIBUS Master stationcan not communicate withthe HART slave device,when “RUN LED” of theGW-7557 is light and “ERRLED” of the GW-7557 isdark.a. Please confirm the GW-7557 doesn’t clear diagnosticmessage by communication command (please refer to section4.6.2).b. Please confirm the connection between the GW-7557 andModbus device.c. If HART Frame Format is “Transparent”, please confirm theoutput data put in correct address and have changed value ofbyte 0 to trigger this command, when output data can notsend to HART slave device in output data area of PROFIBUSMaster.d. If HART Frame Format is “Compact”, please confirmmodule parameters of HART Command module are correct.The user can also use “Scan Device Configuration” functionand “Device Test” function of utility to test communicationbetween GW-7557 and HART slave device.