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| en:software:devices:modbus [2016/12/21 17:03] – [Read Input] qem103 | en:software:devices:modbus [2016/12/21 17:06] – [Read Input] qem103 |
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| === Read Coil === | === Read Coil === |
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| Read bit function. You want to read the bits of a slave (//idcar//d). Sets the parameter //type// = 1.\\ You must set //addr// to indicate the address of the bit in the slave from which to start reading. The //num// parameter indicates the number of bits that are read. You must to set //tabreg// to indicate the index of the bit in the “data read table” the master from which you want to be written the read bits. The raedings value will be saved in the “data read table”. It is recommended to always meet the following two conditions:\\ | Bit read function. You want to read the bits of a slave (//idcar//d). Sets the parameter //type// = 1.\\ You must set //addr// to indicate the address of the bit in the slave from which to start reading. The //num// parameter indicates the number of bits that are read. You must to set //tabreg// to indicate the index of the bit in the “data read table” the master from which you want to be written the read bits. The raedings value will be saved in the “data read table”. It is recommended to always meet the following two conditions:\\ |
| (//addr// + //num// - 1) <= 512 e (//tabreg// + //num// - 1) <= 512 otherwise the request will fail (reporting by //wcmd//). | (//addr// + //num// - 1) <= 512 e (//tabreg// + //num// - 1) <= 512 otherwise the request will fail (reporting by //wcmd//). |
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| === Read Input === | === Read Input === |
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| Bit read function. Si vogliono leggere i bit di un certo slave (//idcard//). La funzione è identica alla “//Read Coil//”. Viene impostato il parametro type = 2.\\ Il significato delle due funzioni si distingue a livello di protocollo MODBUS. Alcuni slave possono mettere a disposizione delle zone di memoria differenti a seconda se i bit letti sono Coil o Input. Nel caso di slave Qmove le due richieste hanno lo stesso effetto. | Bit read function. To read the bits of a slave (//idcard//). The function is equal to the “//Read Coil//”. Sets the parameter type = 2.\\ The meaning of the two functions is distinguished at the level of MODBUS protocol. Some slave can make available different memory areas depending if the bits are Coil or Input. In the case of slave Qmove the two requests have the same effect. |
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| === Read Holding Register === | === Read Holding Register === |