New point type window
Figure 39. New point type properties
You access these properties from the point manager view by clicking the New button.
| Property | Value | Description |
|---|---|---|
| Type to Add | drop-down list | Selects the type of point. |
| Number to Add | number | Selects the number of instances of point. |
| Starting Address | number between 1 and 247 | Defines the first unique device number to assign in a group of Modbus devices. |
| Data Type | drop-down list | Selects the location of the data in the slave device. Coils store on/off values. Registers store numeric values. Each coil or contact is 1 bit with an assigned address between 0000 and 270E. Each register is one word (16 bits, 2 bytes) as well as a data address between 0000 and 270E. |
Modbus proxy points
Modbus client and server proxy points are similar to other driver proxy points. The same collection of client proxy points is used in devices under a ModbusAsync, ModbusTcp, ModbusTcpGateway, ModbusSlave and ModbusTcpSlave network components. You can find them in the client Points folder in the palettes (modbusAsync, modbusTcp, modbusSlave and modbusTcpSlave).
| Proxy point type | Client (master) usage | Server (slave) usage |
|---|---|---|
| Boolean Writable | Reads and writes a Modbus coil. | Reads and writes a virtual Modbus coil or input.
Generally, it is unwise to expose any coil as BooleanWritable if the Modbus master may also write to this same item—otherwise write contention issues may result. |
| Boolean Point | Reads either a Modbus coil or an input. | Reads a virtual Modbus coil that may be written by the Modbus master. |
| Numeric Writable | Reads and writes a Modbus holding register value. You must specify the Data Type as either integer, long, float, or signed integer.
|
Reads and writes a virtual Modbus holding register value or input register value. You must specify the Data Type as either integer, long, float, or signed integer.
Generally, it is unwise to expose any holding register as NumericWritable if the Modbus master may also write to this same item—otherwise write contention issues may result. |
| Numeric Point | Reads either a Modbus holding register value or an input register value. You must specify the Data Type as either integer, long, float, or signed integer.
|
Reads a virtual Modbus holding register value that may be written by the Modbus master device. You must specify the Data Type as either integer, long, float, or signed integer. |
| Register Bit Writable | Reads and writes a specific bit in a Modbus holding register (select Bit Number in setup). | Reads and writes a specific bit in a virtual Modbus holding register or input register (select Bit Number in setup).
Generally, it is unwise to expose any holding register as a RegisterBitWritable if the Modbus master may also write to this same item—otherwise write contention issues may result. |
| Register Bit Point | Reads a specific bit in either a Modbus holding register or an input register (select Bit Number in setup). | Reads a specific bit in a virtual Modbus holding register (select Bit Number in setup) that may be written by the Modbus master. |
| String point | Reads some number of consecutive Modbus holding registers and interpret them as an ASCII string, using a high-to-low byte order. In general, use of this type is expected to be infrequent. | Reads some number of consecutive virtual Modbus holding registers that may be written by the Modbus master, and interpret them as an ASCII string, using a high-to-low byte order. In general, use of this type is expected to be infrequent. |
| Enum Bits Writable | Reads and writes some number of consecutive bits within a holding register, with the resulting integer as the out (ordinal) value of the Enum Writable. | N/A |
| Enum Bits Point | Reads some number of consecutive bits within a holding or input registering the resulting integer as the out (ordinal) value of the Enum Point. | N/A |
| Numeric Bits Writable | Reads and writes some number of consecutive bits within a holding registering the resulting integer as the out value of the Numeric Writable. | N/A |
| Numeric Bits Point | Reads some number of consecutive bits within a holding or input registering the resulting integer as the out value of the Numeric Point. | N/A |