Omron SYSDRIVE 3G3RV Series User Manual page 307

nConverting Register Data
Register data (such as monitor values or parameter set value data) is placed in the communications data block
of the message data (i.e., request message or response data). The data in each register is sent as 2-byte data. It
is processed under the following rules and sent in hexadecimal.
The data is converted to a hexadecimal value using a minimum setting unit for each register of
1
For example, if the frequency reference is 60 Hz and the minimum unit of setting is 0.01 Hz, the data will be
converted as follows:
60 Hz/0.01 (Hz) = 6000 = 1770 Hex
The minimum unit of setting of each parameter is given in the description of the parameter and in the parame-
ter tables in Chapter 5 Parameters.
The minimum unit of setting of frequency reference data or frequency monitor data is determined by o1-03
(register 502 Hex: frequency reference/monitor unit selection). The unit of setting of each of the three registers
below is determined by the set value in o1-03. The set value in o1-03 has nothing to do with frequency data
items set as parameters (e.g., frequency references 1 through 16, inching frequency reference, maximum fre-
quency, minimum output frequency, jump frequency). For these items, the unit of setting is as shown in Chap-
ter 5 Parameters.
• Monitor Items
Register 0023H: Frequency reference monitor
Register 0024H: Output frequency monitor
• Communications Register
Register 0002H: Frequency reference
In spite of the set value in o1-03, however, set the maximum frequency to 30000 when the frequency refer-
ence is executed with a broadcast message. In this case, the Inverter rounds off any value less than 0.01 Hz.
If the jump frequency is 100.0 Hz and the minimum unit of setting is 0.01 Hz, the data will be converted as
follows:
100.0 (Hz)/0.01 (Hz) = 10000 = 2710 Hex
Negative values are expressed in 2's complements
If the frequency bias in H3-03 is -100%, the minimum unit of setting will be 1% and the data will be converted
as follows:
100 (%)/1 (%) = 100 = 0064 Hex
2's complement: FF9C Hex
0064 Hex
Whether the data is positive or negative is determined by the parameter set value.
The MSB of negative-value data is always set to 1. Data with its MSB set to 1 is not, however, always nega-
tive-value data.
For example, the setting range of parameter d3-01 (register 294 Hex: jump frequency 1) is within a range from
0.00 to 400.0 Hz. If the jump frequency is 400.0 Hz, the data is obtained from the following formula and its
0 0 0 0 0 0 0 0 0 1
Bit reversed.
1 1 1 1 1 1 1 1 1 0
1 is added.
1 1 1 1 1 1 1 1 1 0
Fig 6.61
Communications Functions
1 0 0 1 0 0
0 1 1 0 1 1 FF9B Hex
0 1 1 1 0 0 FF9C Hex
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