6.3 Data
6.3.1 Notes about Write/Read Command
• The data (set value, decimal) is converted to hexadecimal numbers.
Negative numbers are represented in 2's complement.
• When connecting multiple slaves, the address (instrument number) must not be duplicated.
• Do not use undefined Data items. If they are used, negative acknowledgement will be returned or a random
value will be written or read, resulting in malfunction.
• Modbus uses Holding Register addresses. The Holding Register addresses are created as follows. A Shinko
command data item is converted to decimal number, and the offset of 40001 is added. The result is the
Holding Register address.
Using Data item 0001H (SV1) as an example: Data item in the sending message is 0001H, however,
Modbus Holding Register address is 40002 (1 + 40001).
6.3.2 Write Command
• Up to 1,000,000 (one million) entries can be stored in non-volatile IC memory.
If the number of settings exceeds the limit, the data will not be saved. So, do not change the set values
frequently via software communication. (If a value set via software communication is the same as the value
before the setting, the value will not be written in non-volatile IC memory.)
• Setting range of each item is the same as that of keypad operation.
• When data (set value) has a decimal point, a whole number (hexadecimal) without a decimal point is used.
• If any action is changed in [Event output EV1 allocation] or [Event output EV2 allocation], the EV1 alarm
value, EV2 alarm value, etc. will revert to factory default value.
For the items to be initialized: Refer to Section “6.6 Items to Be Initialized by Changing Settings” (pp. 55,
56).
• Writings via software communication are possible while in Set value lock status.
• Even if options are not ordered, writing via software communication will be possible. However, their command
contents will not function.
• The Instrument Numbers and Communication Speed of the slave cannot be set by software communication.
They can only be set via the keypad.
• When sending a command by Global address FF (MEWTOCOL) or Broadcast address 00H (Modbus), the
same command is sent to all the slaves connected. However, the response is not returned.
6.3.3 Read Command
• When the data (set value) has a decimal point, a whole number (hexadecimal) without a decimal point is
used for a response.
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