User`s manual

109
Setting the Communications Data Chapter 7-6
7-6 Setting the Communications Data
The following description provides information on how to convert the register
data (such as monitor value or parameter set value data) in the
communications data block of the message data (such as DSR and response
data).
Converting the Register Data
• The data in each register is sent as 2-byte data.
• The data in each register is processed under the following rules and sent
in hexadecimal.
The data is converted to a hexadecimal value based on the minimum
unit of setting of each register as 1.
If the frequency reference is 60 Hz and the minimum unit of setting will
be 0.01 Hz, the data will be converted as follows:
60 (Hz)/0.01 (Hz) = 6000 = 1770 Hex
Note 1. The minimum unit of setting of each parameter is indicated whenever the
parameter is explained in Section 10 List of Parameters. For registers other
than those of parameters, refer to 7-7 Register Number Allocations in
Detail.
2. The minimum unit of setting of frequency reference data or frequency
monitor data is determined by n69 (register 0145 Hex: RS-422A/485
communications frequency reference/monitor unit selection). The unit of
setting of each of the three registers below is determined by the set value
in n69. For the units of setting of these constants, refer to the List of
Parameters. The set value in n69 has nothing to do with frequency data
items set as parameter constants (e.g., frequency references 1 through 8,
inching frequency reference, maximum frequency, minimum output
frequency, jump frequency).
• Monitor Items
Register 0023: Frequency reference monitor
Register 0024: Output frequency monitor
• Communications-dedicated Register
Register 0002: Frequency reference
In spite of the set value in n69, however, set the maximum frequency to
3000 when the frequency reference is executed with a broadcast
message. In this case, the Inverter rounds off any value less than 0.01 Hz.
3. There are parameters that make setting unit changes when the values are
increased with the Digital Operator. The smaller units are, however, used
for communications in such cases. For example, the value in n49 (register
0131 Hex: jump frequency 1) will be set in 0.01-Hz increments if the
frequency is less than 100 Hz and 0.1-Hz increments if the frequency is
100 Hz or over. The value 0.01 Hz is always 1 Hex for communications.
If the jump frequency is 100.0 Hz, the minimum unit of setting will be
0.01 Hz and the data will be converted as follows:
100.0 (Hz)/0.01 (Hz) = 10000 = 2710 Hex