User Manual of EM730 Series Inverter 11.4 Protocol Description 11.4.1 Definition of inter-frame and intra-frame time interval starting and ending tags. Thus, as shown in Fig. 12-20 or Fig. 4-22, the idle level with a A complete MODBUS message contains not only the necessary data units, but also the transmission time of 3.5 characters or more is defined as the starting and ending tag. If there is an idle level with a transmission time of more than 1.5 characters during message transmission, the transmission will be deemed exceptional. Specific starting/ending and exception intervals are related to the baud rate, as detailed in Table 4-34.
If the baud rate is 9600bps and the sampling period is 1ms, the starting and ending time interval is the idle level of 4ms or more (3.5Ч10/9600=3.64≈4), and the exceptional data interval is the idle level in which the interval of data bits of one frame is greater than or equal to 2ms (1.5Ч10/9600=1.56≈2) and less than 4m (the idle level of normal data bits is less than or equal to 1ms). Table 4- 34 Correspondence between Time Interval and Baud Rate (t adjust =1ms) 390 address allowed. In particular, the combination of the start address of the register and the transmission length is invalid (see 11.3.4Register address distribution).
03H Illegal data frame The slave station (inverter) has detected the incorrect query data frame length or CRC check. 04H Slave protection When the slave station (inverter) tries to execute a requested operation, an unrecoverable error occurs. This may be caused by the logic error, failure to write to the EEPROM, etc. 05H Data over-range The data received by the slave station (inverter) is not between the minimum and maximum values of the corresponding register. 06H Parameter read-only The current register is read-only and cannot be written. 07H Unchangeable parameter in running When the inverter is in the running status, the current register cannot be written.
If necessary, please shut down the inverter. 08H Parameter protection by password The current register is protected by a password. Correspondence between Time Interval and Baud Rate (t =1ms) adjust Starting and ending time interval T interval (t ) adjust Exception interval T exception (t ) adjust Remarks