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:
| Name | Description | ID | Flags |
|---|---|---|---|
| Description | A description of what this item does. This is free text, so you can write anything you like here. | 101 | Persisted |
| Direction | Direction of data. Input (false) or Output (true). | 5040 | Persisted |
| Byteorder | Only valid when Valutype is Unicode String or ASCII, overrides module property Byteorder. | 10013 | Persisted, Enumerated |
| Check range | Validate range of value, set by Hi Range and Lo Range | 10200 | Persisted |
| Endian1 | Only valid when the Valuetype property is set to "Unicode String" or "ASCII". This property overrides the module's endian. | 10012 | Persisted, Enumerated |
| External quality tag | External tag overriding quality. | 100040 | Persisted |
| External quality mask | Bitmap representing quality bits field, when External quality tag is used. | 100041 | Persisted |
| External pattern bad quality | Bit pattern determinating bad quality, when External quality tag is used | 100042 | Persisted |
| External mask unertain quality | Bit pattern determinating unsertain quality, when External quality tag is used. | 100043 | Persisted |
| EvaluationOrder2 | What order to use to evaluate the values | 10020 | Persisted, Enumerated |
| Hi Range | Upper limit of range | 10201 | Persisted |
| Lo Range | Lower limit of range | 10202 | Persisted |
| Modulus | Value = registerhigh x Modulus + registerlow. Valid only for 4 byte signed and unsigned int | 10015 | Persisted, Enumerated |
| Offset | The linear transformation addend to use when calculating and item value. (Value = RawValue \times Scale + Offset) | 5006 | Persisted |
| 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. | 3 | ReadOnly |
| Read single3 | Force master to read this item only in a single request. | 10032 | ReadOnly |
| Rights | Item access rights - this property may be "read", or "read write". | 5 | ReadOnly |
| Scale | The linear transformation multiplier to use when calculating the item value. | 5005 | Persisted |
| Slaveaddress | The slave address (Unit ID) of the Modbus slave (overrides the module property). | 10030 | Persisted |
| SrcItemID | The item ID in the source. This is the item ID this item uses to fetch data from the source. | 5030 | Persisted |
| StringSize | The number of buffers to read. Only valid when "Valuetype" is "Unicode String" or "ASCII". | 10011 | Persisted |
| Time | The date and time when this item was last updated. | 4 | ReadOnly |
| Type | The item canonical data type - the specific type of this item. Whether it's an integer, string, date, etc. | 1 | ReadOnly |
| Unit | EU units - this is the unit this item value uses. For example: centimetres, kilograms, kilowatts, etc. | 100 | Persisted |
| Value | The current value of the item. | 2 | NormalPage |
| Valuetype | Item canonical datatype. This is the type of data the field holds. For example: integer, string, datetime, etc. | 10010 | Persisted, Enumerated |
| Write immediately | Send value immediately to slave on set value independet of polling rate (Valid only when Direction = true). | 10125 | NormalPage |
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.
EvaluationOrder:
- 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.
- Slave no writeback: Same as Slave but with no writeback.
Read Single: Used to optimize error handling. WARNING: Enabling this feature on numerous items will affect overall performance.