QueryDevice

Writes data to either a specified TCP/IP server device or a UDP server device, then reads the data back from that device. The response from the device must be received before the device's Timeout limit is reached.

Note: The primary use of this function is to retrieve binary data packets from a Modbus server. For more information, see Binary Text Functions or Modbus TCP Communications.

QueryDevice Inputs

Syntax: QueryDevice(Event,Device,Data)

Parameter	Description
Event	Specifies the spreadsheet event that triggers the data to be written to the TCP/IP device. This parameter must be a reference to one of the following: The Image data structure in cell A0, containing the AcquireImage function. For more information, see AcquireImage. A cell containing an Event function. For more information, see Event. A cell containing a Button function. For more information, see Button.
Device	A reference to a Device structure, which must be a TCP/IP client, created by a TCPDevice, or a reference to a Device structure returned by a UDPDevice function. For more information, see TCPDevice or UDPDevice.
Data	The data to be written to the TCP/IP or UDP device. For the TCP/IP implementation, the data type must be of the same type specified in the device's Packet Type: either an ASCII string or a binary Modbus command. For the UDP implementation, the data type must be of the same type specified in the Binary Packet parameter: either binary data packets or string information. For more information, see Packet Type or Binary Packet.

Parameter

Description

Event

Specifies the spreadsheet event that triggers the data to be written to the TCP/IP device. This parameter must be a reference to one of the following:

The Image data structure in cell A0, containing the AcquireImage function. For more information, see AcquireImage.
A cell containing an Event function. For more information, see Event.
A cell containing a Button function. For more information, see Button.

Device

A reference to a Device structure, which must be a TCP/IP client, created by a TCPDevice, or a reference to a Device structure returned by a UDPDevice function. For more information, see TCPDevice or UDPDevice.

Data

The data to be written to the TCP/IP or UDP device. For the TCP/IP implementation, the data type must be of the same type specified in the device's Packet Type: either an ASCII string or a binary Modbus command. For the UDP implementation, the data type must be of the same type specified in the Binary Packet parameter: either binary data packets or string information. For more information, see Packet Type or Binary Packet.

QueryDevice Outputs

Returns

A Query data structure, or #ERR if any of the input parameters are invalid.

For more information, see Input/Output Functions, Binary Text Functions, ReadDevice, or WriteDevice.