Properties

16 bit word Read-Write Starting address 0x40001 to 0x4FFFF when address mapping is active or 0 to FFFF when addressmapping deactivated

The HoldingRegister item type has the following properties:

NameDescriptionIDFlags
Description

A description of what this item does. This is free text, so you can write anything you like here.

101Persisted
Direction

Direction of data. Input (false) or Output (true).

5040Persisted
Byteorder

Only valid when Valutype is Unicode String or ASCII, overrides module Byteorder. Byte transfer orde

10013Persisted, Enumerated
Endian

Only valid when the Valuetype property is set to "Unicode String" or "ASCII". This property overrides the module's endian. Modbus is a "big-endian" protocol: that means the more significant byte of a 16-bit value is sent before the less significant byte. Be careful with 32-bit and 64-bit values, which may not be transferred using big-endian order. Some manufacturers treat 32-bit and 64-bit values as being composed of 16-bit words, and transfer the words in little-endian order. For example, the 32-bit value 0x12345678 would be transferred as 0x56 0x78 0x12 0x34. Select LittleEndian to use this mixed ordering.

10012Persisted, Enumerated
External quality tag

External tag overriding quality.

100040Persisted
External quality mask

Bitmap representing quality bits field, when External quality tag is used.

100041Persisted
External pattern bad quality

Bit pattern determinating bad quality, when External quality tag is used.

100042Persisted
External mask unertain quality

Bit pattern determinating unsertain quality, when External quality tag is used.

100043Persisted
EvaluationOrder

 

What order to use to evaluate the values:

Apis: The value is written to the slave on every cycle;

Slave: The value is read from the slave before the write. The value is only written to the slave when its changed in Apis.

10020Persisted, Enumerated
ModulusValue = registerhigh x Modulus + registerlow. Valid only for 4 byte signed and unsigned int10015Persisted, Enumerated
Offset

The linear transformation addend to use when calculating and item value. (Value = RawValue * Scale + Offset)

5006Persisted
Quality

Item quality - this tells you whether an item currently has a good or bad quality. It might be bad, for example, because it isn't connected or is set to the wrong type.

3ReadOnly
Rights

Item access rights - this property may be "read", or "read write". This means that the property may only be read from, or also can be written to. For OPC items, this written value will be passed on to the external items this item comes from.

5ReadOnly
Scale

The linear transformation multiplier to use when calculating the item value. (Value = RawValue * Scale + Offset)

5005Persisted
Slaveaddress

The slave address (Unit ID) of the Modbus slave (overrides the module property).

10030Persisted
SrcItemID

The item ID in the source. This is the item ID this item uses to fetch data from the source.

5030Persisted
StringSize

The number of buffers to read. Only valid when "Valuetype" is "Unicode String" or "ASCII".

10011Persisted
Time

The date and time when this item was last updated.

4ReadOnly
Type

The item canonical data type - the specific type of this item. Whether it's an integer, string, date, etc.

1ReadOnly
Unit

EU units - this is the unit this item value uses. For example: centimetres, kilograms, kilowatts, etc.

100Persisted
Value

The current value of the item.

2NormalPage
Valuetype

Item canonical datatype. This is the type of data the field holds. For example: integer, string, datetime, etc.

10010Persisted, Enumerated
Write immediately

Send value immediately to slave on set value independet of polling rate (Valid only when Direction = true).

10125NormalPage

See also

Basic Item Properties

Predefined Item Properties

OPC DA Properties