SerialInBlock (Store Incoming Serial Data)

The SerialInBlock function stores incoming serial data. This function returns the number of bytes received.

Syntax

SerialInBlock ( ComPort, Dest, MaxNumberBytes )

In the following example, the datalogger is put into a transparent communication mode. Any data coming in on the datalogger's RS232 port are sent out the datalogger's COM1. Any data coming in on the datalogger's COM1 are sent out the datalogger's RS232 port.

The SerialInBlock function is used to set the NumberBytes parameter in the SerialOutBlock instruction.

Public Str as STRING * 1000

'Main Program
BeginProg
  'Open RS232 port at 115.2K baud
  SerialOpen (ComRS232,115200,0,0,1000)
  'Open COM1 at 9600 baud
  SerialOpen (COMC1,9600,0,0,1000)

  Scan (1,Sec,3,0)
    'Send data out COM1; set NumberBytes to the size of the incoming string
    SerialOutBlock (COMC1,Str,SerialInBlock(ComRS232,Str,1000))
    'Send data out RS232 port, set NumberBytes to the size of the incoming string
    SerialOutBlock (ComRS232,Str,SerialInBlock(COMC1,Str,1000))
  NextScan
EndProg

Remarks

Incoming serial data, up to the value defined in MaxNumberBytes, is stored in the Dest parameter. SerialInBlock will not wait for the return of characters. If no new characters are received since the last execution of the function, 0 is returned by the function. This function can be used as the expression for the NumberBytes parameter in the SerialOutBlock function. For incoming data, extended ASCII characters (128-255) are supported only by SerialOpen format options 1-7 and 17-23.

NOTE: This function runs sequentially from the processing task sequencer, regardless of whether the datalogger is in pipeline or sequential mode. When SerialIn, SerialOut, SerialInBlock, and/or SerialOutBlock are used to access a COM port, the instructions should be placed in the same sequence (main program or slow sequence) to avoid unintentional concurrent reads or writes of that port.

This instruction can also be used along with other serial instructions to set up and control the SDM-SIO1A or SDM-SIO4A or SDM-SIO2R.

Parameters

ComPort_Serial_In (Communications Port Serial In)

The COM port that will be used by the instruction. Right-click to display a list.

Alphanumeric Description
ComRS232 RS232 port of the datalogger
ComMe Datalogger's CS I/O port;modem enabled
Com310 Datalogger's CS I/O port; Com310 modem
Com320 Datalogger's CS I/O port; Com320 modem
ComSDC7 Datalogger's CS I/O port; SDC7
ComSDC8 Datalogger's CS I/O port; SDC8
ComSDC10 Datalogger's CS I/O port; SDC10
ComSDC11 Datalogger's CS I/O port; SDC11
ComC1 Datalogger's control ports 1 (TX) & 2 (RX)
ComC3 Datalogger's control ports 3 (TX) & 4 (RX)
ComC5 Datalogger's control ports 5 (TX) & 6 (RX)
ComC7 Datalogger's control ports 7 (TX) & 8 (RX)

Type: Constant. For all instructions except SerialOpen, this parameter can also be a variable. However, if a variable is used, the port must be opened previously by SerialOpen (Open Communication Port)

For the SerialInBlock instruction, the ComPort parameter specifies the communication port and mode that is used when receiving the binary data. A variable can be used in the ComPort parameter for use with functions that return a communication port. If communication occurs using TCP/IP, enter the variable for the socket returned by TCPOpen.

NOTE: When using the ComME ComPort with non-PakBus protocols (PPP, Modbus, DNP3, or generic serial applications), incoming characters can be corrupted by concurrent use of the CS I/O port for SDC communication (e.g., keyboard display).

Dest (Destination)

The Variable in which to store the results of the instruction. Right-click the parameter to display a list of defined variables.

If this instruction has a Repetitions parameter and it is greater than 1, the results are stored in an array with the variable name. The array must be dimensioned large enough to hold all of the values returned from all of the Reps.

Type: Variable or Array

NOTE:
Beginning with OS 7, a variable of type UINT1 may be used (See also Data Types.). Arrays of UINT1 variables can be used to store binary data received from serial sensors allowing easier processing of that data, compared to string variables.

For the SerialInBlock instruction, the Dest parameter is the variable in which to store the incoming serial data. Once the MaxNumberBytes of incoming data is received, no more data is stored. Note that Dest is not reset to null if no new characters are received. The program can be written to ignore Dest if the instruction returns 0, or to process Dest for the number of characters received at each execution.

 

MaxNumberBytes (Maximum Number of Bytes)

The maximum number of bytes of binary data that will be stored in the Dest parameter.

Type: Constant (or variable or expression evaluated as a constant)