System pro M compact® - Piti Group

Systempro M compact ®Technical detailsDigital measurement instrumentsMeasurementdevicesUnicastmodeThe protocol has one Master and up to 247 Slaves on acommon line covering a maximum distance of 1200 metres.Only the Master initiates transactions. The transactions areof the request/reply type (addressed to a single Slave) or ofthe broadcast/reply type (addressed to all Slaves).Modbus is often used for connecting a supervisory computerwith a remote terminal unit (RTU) in supervisory control anddata acquisition systems (SCADA). There are two versions ofthe protocol: one for serial ports (RS232 by default, but alsoRS485) and one for Ethernet.SLAVE SLAVE SLAVE SLAVEModbus uses a compact hexadecimal data representation.The RTU format appends to commands/data a cyclic redundancychecksum (CRC) field, while the ASCII format uses anLRU type (longitudinal redundancy check) checksum.BroadcastmodeSLAVE SLAVE SLAVE SLAVEDMTME-I-485-96DMTME-I-48510Up to 1200 mUp to 247 devicesCUSANR96-230Selection tables ............................. pag. 8/36ABB10/145