Download E7 Drive Parameter Access Technical Manual
Transcript
Write Single Register – Function Code 06H The Write Single Register function allows the writing of data to one register only. ► Write Single Register Command Message Table 2.5 - Write Command Message Description Slave Address Function Code Upper Lower Upper Lower Upper Lower Register Address Data CRC-16 Data 01h 06h 00h 01h 00h 03h 98h H0B Each E7 drive slave address is set via. parameter H5-01. Valid slave addresses must be in the range of 1 to 20 hex (1 to 32 dec) and entered as a hexadecimal number. No two slaves may have the same address. The master addresses the slave by placing the slave address in the Slave Address field of the message. In the command message above, the slave is addressed at 01h. Broadcast address 0 is valid for register write commands. By setting the slave address to zero (0) in the command message, the master can send a message to all the slaves on the network simultaneously. This is called simultaneous broadcasting. In a simultaneous broadcast message there is no response message. The function code of this message is 06h (write single register). In the command message above the register address is 01h (0001h). The data section contains the data to be that written. A CRC-16 value is generated from a calculation including the message slave address, function code, starting register, quantity, number of data bytes and all register data. The procedure for calculating a CRC-16 is described at the end of this chapter. When the slave receives the command message it calculates a CRC-16 value and compares it to the CRC-16 of the command message. If the two CRC-16 values are identical and the slave address is correct, the slave processes command message. If the two CRC-16 values are not identical, the slave will discard the command message and not respond. If the command message has a valid slave address, function code, register address and data, the slave will respond with a normal response message. If the command message has an invalid function code, register address and/or data, the slave will respond with a fault response message. If the command message has an invalid slave address or CRC-16, no response will be returned. Message Formats 2-6