Omron 3G3MV-PDRT2, Руководство пользователя

Страница: 148 / 363

Chapter 6
6-18
Message Communications
6-7 Reading and Writing Parameters: Class 64 Hex
Inverter parameters can be read and written using explicit messages. Class 100 decimal (64 hex)
has been provided with instances and attributes corresponding to each parameter in the Inverter.
Send an explicit message to the class, instance, or attribute of the parameter to be set as described
below.
■
Parameter Database
All parameters in the parameter database have been unified to 1-word (16-bit) data. Even settings of
0 and 1 will be treated as 1-word (16-bit) data in explicit messages.
Note When sending or receiving 1-word (16-bit) data in an explicit message, the leftmost and right-
most bytes will be reversed. Accordingly, when reading or writing data, the attribute value will
be in the upper byte, the lower byte will contain the lower byte of the data, and the upper byte
of the data will be in the upper byte of the next word.
• Communications line data is sent and received in the order of lower byte, then upper byte.
• PLC internal processing data, such as when sending commands, are sent and received in the
order of upper byte, then lower byte.
■
Parameter Read and Write Data
Read data and write data for parameters is calculated as shown below and then transmitted in hexa-
decimal.
• Convert to hexadecimal values with the function/parameter minimum setting unit taken as 1.
Example: To set a frequency reference of 60 Hz when the minimum setting unit is 0.01 Hz.
60/0.01 = 6000
→
1770 hex
• Negative numbers are expressed as two's complements. (A 3G3MV is used in this example).
Example: To set a frequency reference bias (n061) of -100% when the minimum setting unit is 1%:
100/1 = 100 decimal = 0064 hex,
−
100%
→
FF9C hex
• If the original data is already in hexadecimal, it is transmitted as is.
Note All parameters in the 3G3MV Series are in decimal, so convert them to hexadecimal.
• Set bits that are not used to “0.”
• Do not set data for unused registers.
0 0 0 0 0 0 0 0 0 1 1 0 0 1 0 0
1 1 1 1 1 1 1 1 1 0 0 1 1 0 1 1
1 1 1 1 1 1 1 1 1 0 0 1 1 1 0 0
+1
= FF9C Hex
= FF9B Hex
0064 Hex =
Bit reversal