Sepam - HV/MV Protection and control units (ENG) - Trinet

AnnexesDifferences between Jbus and Modbusframe structure Jbus Modbusslave number 1 to 255 1 to 247function code 1 to 16 (except for 9 and 10) 1 to 21frame width 255 bytes max. 261 bytes max.CRC CRC16 CRC16frame detection* silence > 3 characters silence > 1.5 or > 3.5 charactersdata addresses 0 to FFFF depending on manufacturer 0 to FFFF or 0 to 9999* This difference does not create any problems with rates higher than 1200 bauds since these times are less than the equipment processing time (response time).standard functionsfunction 1 reading of n bits reading of n bitsfunction 2 reading of n bits reading of n bitsfunction 3 reading of n words reading of n wordsfunction 4 reading of n words reading of n wordsfunction 5 writing of 1 bit writing of 1 bitfunction 6 writing of 1 word writing of 1 wordfunction 7 fast reading of 8 bits reading of exception status (8 bits)indicates faults on equipmentfunction 15 writing of n bits writing of n bitsfunction 16 writing of n words writing of n wordsThe information below is given for information purposes and does not necessarily concern Sepam 2000.extended functions** (sub-functions)function 13 program commands program commands(01-02) identical identical(03-04) address on 24 bits address on 16 bits + 8 bits for page n°address extension(25) identical identical(26) data byte = 00 or 80h data byte = 06hfonction 14 identical identicalPlease note: function 13 has 43 sub-functions, Jbus only uses 6 of them.diagnosis functions (sub-functions)function 8 reading of diagnosis counters reading of diagnosis counters(01)** data = 0000 => no reply sent replydata = FF00 zero reset of countersno zero reset of counters(00-02**-03**-0A) identicalidentical(0B) not incremented after broadcast incremented with broadcast(0C - 0D) identical identical(0E) not incremented after broadcast incremented with broadcast(0F) counts the number of broadcasts received counts the number of non-replies from slave(10-11) identical identical(12) counts character errors (format, parity,..) counts overrunsfunction 11 even counter even counterincremented with broadcastnot incremented with broadcastin the reply, the 1 st word is always at 0in the reply, the 1 st word is at 0 or FFFF (status)function 12 ** history of last 64 exchanges history of last 64 exchangesin the reply, the 1 st word is always at 0in the reply, the 1 st word is at 0 or FFFF (status)exception codes0 -02-03-05-07-08** identical identical04 equipment not ready error during processing of query09** overlapping of memory zone not implemented** does not concern Sepam 2000.Jbus/Modbus communication47