Delta Driver 

The Delta Driver supports both PLC and VFD (variable frequency drive) devices from Delta Electronics. Users can select a product type and model from the configuration folder, then within their I/O tags use an Address Assist dialog to build addresses that are compatible with the protocol for the selected device.

The communication protocol is standard Modbus, with RTU, ASCII, and TCP supported.

Delta drivers can import tags from a DIADesigner XML file. Configure your driver then use the Import button in the Tag Browser while the driver is selected. Only XML files can be selected. You must have both Tag Add and Tag Modify privileges in order to use this feature. Up to 16,000 tags can be included in one file.

The driver can interface with the following PLC lines. AS, AH, DVP3, DVP, AX, MC, and Delta VFD. Expand the following section for a reference showing which models of PLC fall under each line.

The application must be restarted after changing the hardware type.

 

Server List

Select (or create) a named server list. (Driver Server Lists) Servers for the list must be defined using the Application Configuration dialog, as described in Servers for Specific Services. Smaller sites that do not have multiple servers, or that use only the default server list, need not configure this field.

Delta Driver properties - Options tab

Use the Options tab to select the hardware type and communication mode to be used by this driver.

At present, all communication modes are related to Modbus protocols, as implemented by Delta.

The application must be restarted after changing the hardware type.

Hardware Type

Select the appropriate device type from the list.

Communication Mode

Both Modbus RTU and Modbus ASCII use a serial communication mode

Select Modbus TCP if using an Ethernet communication mode.

Store Last Output Values

When selected, the driver will maintain a record of the last value written to each output address. This may be useful in at least two situations:

  • For hardware that does not maintain its state during a power loss and must be restored to that state when re-started.
  • When failed hardware is replaced by a new device and you would like to start that device with the values last written to the old one.

If the last output values are stored, they may be re-written by either of two methods:

  • Automatically, when communication is restored to the device.
  • Manually by way of a button press. See, Rewrite Outputs Widget for details.

Changing this value from selected to deselected will cause all stored values to be erased immediately.

If this driver is being used in conjunction with a Driver Multiplexer, then configure the Driver Multiplexer to store the last values, not the drivers connected to the Multiplexer. In this case, only the Multiplexer should be configured to re-write automatically.

Enable Auto Rewrite

If selected, the Store Last Output Values option will also be activated. This option causes the driver to rewrite the last value written to each output, in the event that communications are lost and then restored.

Use this option only if you are certain that you want the last values to be rewritten automatically after an interruption in driver communications.

PLC Address

The station address of the Delta programmable logic controller. By default, the PLC Address field is set to 1.

An expression may be used to provide the address if needed. This may be required on a network where the address varies depending on the workstation where the tag is running.

Note that, to create a valid expression for an address that contains non-numeric characters, you must enclose the address in quotation marks. e.g. "31.0.0.0" See: Modbus Plus PLC Addressing.

Squelch Noise Present

Applies when communicating over a modem. Select this box to enable the squelching of background noise. By default, the Squelch Noise Present check box is not selected.

Reverse Long Integer Byte

Select whether byte swapping should occur for long integer values. By default, the Reverse Long Integer Byte check box is not selected.

Reverse IEEE Single Byte

Select whether byte swapping should occur for IEEE single byte values. By default, the Reverse IEEE Single Byte check box is not selected.

Reverse IEEE Double Byte

Select whether byte swapping should occur for IEEE double byte values. By default, the Reverse IEEE Double Byte check box is not selected.

 

Delta Driver properties - Communications tab

Port

Select the Serial Port tag or TCP/IP tag you wish to be associated with this driver tag. A Serial Port tag should be used for Modbus RTU and Modbus ASCII. A TCP/IP port should be used for Modbus TCP.

Time-Out Limit

Set the receiver time-out limit in seconds or fractions of a second. This is the length of time that this driver should wait for a reply from the PLC or RTU.

Retries

The number of times to retry a message before declaring an error.

Use only if the driver is connected to a device that uses a serial port or a UDP/IP port that is configured to be polled. When connected directly to a device using TCP/IP, this value should normally be set to 0 since TCP/IP is a guaranteed message delivery protocol.
For unreliable communications, such as radio, set to 3 or 4.

Retry Delay

The Retry Delay field enables you to specify the amount of time (in seconds or fractions of a second) that the driver will wait between attempts to repeat a transmission of data if the previous attempt(s) have failed.

By default, the Retry Delay field is set to 0 (indicating that there should be no delay between retry attempts).

Hold

Select this to have I/O tags attached to the driver hold their last value in the event of a communication failure. If not selected, tags will have their value set to invalid on a communication failure.

RTS Key Off Delay

The RTS Key Off Delay field represents the amount of time (in seconds) that this Delta Driver will wait before dropping RTS at the end of a data transmission.

Squelch Time

Sets the amount of time (in seconds or in fractions of a second) to wait before clearing noise. Enabled only when Squelch Noise Present has been selected on the Options tab.