6
TROUBLESHOOTING ........................................................................................................................ 35
6.1 INTERMITTENT OR NO COMMUNICATION ........................................................................................... 35
6.2 MODBUS ERRORS: EXCEPTION RESPONSES .................................................................................... 35
6.3 DATA INVALID – OUTSIDE OF DATA RANGES ..................................................................................... 36
7 SCADA PROGRAMMING EXAMPLES .............................................................................................. 38
7.1 SIMPLE REGISTER READS ............................................................................................................... 38
7.2 TWO-REGISTER DATA READS .......................................................................................................... 39
7.3 READING INVALID DATA ................................................................................................................... 41
7.4 SECURITY – READING AND GAINING ACCESS .................................................................................... 42
7.5 REAL TIME CLOCK .......................................................................................................................... 44
7.6 READING ASCII DATA ..................................................................................................................... 44
7.7 READING AND SETTING VOLTAGE BIAS ............................................................................................. 45
7.8 READING ANALOG INPUTS ............................................................................................................... 46
7.9 READING EVENT DATA .................................................................................................................... 48
7.10 READING AND INTERPRETING ALARM GROUP DATA ....................................................................... 55
APPENDIX A MODBUS REGISTER DATA ......................................................................................... 59
APPENDIX B INDEX OF MODBUS REGISTERS – ALPHABETICAL ............................................... 83
APPENDIX C INDEX OF MODBUS REGISTERS – NUMERICAL...................................................... 90