Schneider Automation XXMIT Transmit Function Block Function Block Description

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Belge

Reklam

Breite: 185 mm

Höhe: 230 mm

Concept

Version 2.2

XXMIT

Function Block Description

03/2000

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XXMIT: Transmit

1 Brief Description

1.1 Specific Functionality

1.2 Restrictions

1.3 Software and Hardware Required

Software

Hardware

1.4 Memory Requirements

2 Representation

2.1 Symbol

2.2 Parameter Description

3 Detailed Description

3.1 Mode of Functioning

3.2 Parameter Description

Start

Command

MsgOut

MsgLen

Port

Baudrate

Databits

Stopbits

Parity

RespTout

RetryLmt

StartDly

EndDly

Retry

Active

Done

XXMIT

Width: 185 mm

Height: 230 mm

2 XXMIT

Error

MsgIn

RecCount

Status

4 XXMIT Communication Functions

4.1 Terminated ASCII Input Function

Terminated ASCII Example

4.2 Simple ASCII Input Function

4.3 ASCII String Messaging

4.4 Modem Output

Initialize Modem

Pulse Dial Modem

Tone Dial Modem

Hangup Modem

4.5 Modbus Messaging

Modbus Function Codes (01 ... 06, 15 and 16)

Modbus Function Code (08)

Modbus Function Codes (20, 21)

4.6 ASCII Receive FIFO

4.7 Back space and Flow Control

Enable Back space

Enable RTS/CTS Flow Control

Enable Xon/Xoff Flow Control

5 Run Time Errors

6 Application Example

6.1 Description

6.2 Modbus Master

Variable declaration

IEC Section

6.3 Simple ASII Receive

Variable declaration

IEC Section

6.4 Simple ASCII Send

Variable declaration

IEC Section

6.5 Terminated ASCII Receive

Variable declaration

IEC Section

6.6 Entering Strings as initial values

Open the Variable Editor

Define new variable

Enter text as initial value

Look at Array Elements

7 Technical References

7.1 Modbus Query/Response Parameter Limits

7.2 Cable Pinouts

9--pin (RS--232) to 25--pin (Modem) with no RTS/CTS Control

9--pin (RS--232) to 25--pin (Modem) with RTS/CTS Control

9--pin to 9--pin (Null Modem)

9--pin to 9--pin (Modem)

9--pin to 25--pin (Null Modem)

RJ45--(8x8) to 25--pin (Null Modem) 110XCA20401

RJ45--(8x8) to 9--pin (Null Modem)110XCA20301

RJ45--(8x8) to 25--pin (Modem)110XCA20401

XXMIT

Width: 185 mm

Height: 230 mm

RJ45--(8x8) to RJ45--(8x8) (Modem)

9--pin to RJ45--(8x8) (Modem)110XCA20301

7.3 Cable Adapter Kits

7.4 XXMIT Configuration using Hayes Compatible Dial--Up Modems (Only) 61

Initialization Message

Dial Message

Hangup Message

4 XXMIT

Width: 185 mm

Height: 230 mm

1 Brief Description

1.1

Specific Functionality

The XXMIT (Transmit) function block sends Modbus messages from a ”master”

PLC to a slave PLC or sends ASCII character strings from the PLC’s Modbus serial port#1 (on Momentum PLCs port#2 is also supported) to ASCII printers and terminals. XXMIT sends these messages over telephone dialup modems, radio modems, or simply direct connections. XXMIT performs general ASCII input functions in the communication mode including simple ASCII and terminated ASCII. You may import and export ASCII or binary data into your

PLC. The block has builtin diagnostics that checks to make sure no other

XXMIT blocks are active in the PLC on the same port at the same time. Within the XXMIT block control inputs allows you to control the communications link between the PLC and DCE (Data Communication Equipment) devices attached to Modbus port #1 or port #2 of the PLC. The XXMIT block does activate the port LED when it is transmitting data.

Note:

EN and ENO should NOT be used with the XXMIT, otherwise the output parameters may freeze.

This EFB can be found in the COMM library in the RTU subgroup.

Expert:

Remember, the Modbus protocol is a ”master/slave” protocol.

Modbus is designed to have only one master polling multiple slaves. Therefore, when using the XXMIT block in a network with multiple masters, contention resolution and collision avoidance is your responsibility and may easily be addressed through user logic programming.

XXMIT 5

6 XXMIT

1.2

Restrictions

The following restrictions apply to the XXMIT function block:

XXMIT does not support:

ASCII string conversion copy and compare functions

Port Status functions

Note:

Momentum PLCs support only 1 Stop bit

Note:

Port 2 only supported by Momentum PLCs.

Port parameters used in the XXMIT block using port 2 must match the hardware port parameters.

1.3

Software and Hardware Required

Software

The XXMIT function block requires the following software

A minimum of Concept 2.2 Service Release 2

IEC exec version. You must load the new exec file (firmware) into the flash memory of your CPU which is contained on the Service Release 2 CD--ROM.

Hardware

The following hardware is not supported by the XXMIT function block:

PLCs which do not support IEC languages

Soft PLC

ATRIUM PLC

IEC Simulator

For information on the required cables see chapter “Cable Pinouts” on page 49

1.4

Memory Requirements

The usage of one or more XXMIT EFBs in an IEC application consumes approximately 15.5 KByte program (code) memory.

For each instance of this EFB included in the user program, additional data memory between 2.5 and 3 Kbyte is allocated.

Width: 185 mm

Height: 230 mm

XXMIT 7

8 XXMIT

2 Representation

2.1

Symbol

BOOL

WORD

ANY

INT

BYTE

INT

BYTE

INT

XXMIT

Start

Command

Active

Done

MsgOut Error

MsgLen

Port

Baudrate

Databits

Stopbits

Parity

RespTout

RetryLmt

StartDly

EndDly

MsgIn

RecCount

Status

Retry

BOOL

ANY

INT

2.2

Parameter Description

Parameters Data type

Start BOOL

Command

MsgOut

WORD

ANY

MsgLen

Port

Baudrate

Databits

Stopbits

Parity

INT

BYTE

INT

BYTE

RespTout

RetryLmt

StartDly

EndDly

INT

Significance

Value of 1 starts XXMIT operation

Specifies the command to be performed

Message to be sent

Message length of output message

Selection of communications interface

Baudrate

Databits

Stopbits

Parity

Time to wait for a valid response

Number of retries until receiving a valid response

Waiting time before message transmit.

Waiting time after message transmit

Parameters Data type

Active BOOL

Done

Error

BOOL

MsgIn

RecCount

Status

Retry

ANY

INT

Significance

Value of 1 indicates that an XXMIT operation is in progress

Value of 1 indicates that the XXMIT operation has been completed successfully

Value of 1 indicates that an error has occurred or that the current XXMIT operation is terminated.

Incoming message

Displays the number of received characters

Displays a fault code generated by the XXMIT block

I ndicates the current number of retry attempts made by the XXMIT block.

Width: 185 mm

Height: 230 mm

XXMIT 9

3 Detailed Description

3.1

Mode of Functioning

The XXMIT function block provides the same communication functions as its

LL984 XMIT counterpart but uses different programming and parameters: h

It is no longer neccessary to map any input/output parameters into the

4x--Register area.

It is possible to use the datatype ByteArr which allows for an easy string handling.

XXMIT does not support: h

ASCII string conversion h copy and compare functions h

Port Status functions

10 XXMIT

3.2

Parameter Description

Start

A value of 1 at Start initiates the XXMIT operation. The value of 1 must be applied until the operation has finished or until an error has occurred.

Command

The XXMIT interprets each bit of the command word as a function to perform. If bit 7 and 8 are on simultaneously or if any two or more of bits 13, 14, 15 or 16 are on simultaneously or if bit 7 is not on when bits 13, 14, 15, or 16 are on error 129 will be generated. For more details refer to Section 4. The individual bit definitions are shown in the table below.

Bit

1 msb

Figure 1 Command Word Layout

7 8 9 16 lsb

Table 1 XXMIT Command Word Bit Definitions

Bit

Bit 1 (msb)

Bit 2 Enable RTS/

CTS modem control

Bit 3 Enable RS485 mode

Bit 4

Bit 5 Terminated

ASCII input

Bit 6 Simple ASCII input

Bit 7 Enable ASCII string messaging

Bit 8 Enable Modbus messaging

Bit 9 Enable ASCII receive FIFO

Bit 10 Enable back space

Bit 11 Enable RTS/

CTS flow control

Bit 12 Enable Xon/

Xoff flow control

Definition

Reserved

Set to 1 when a DCE connected to the PLC requires hardware handshaking using RTS/CTS control. This bit may be used in conjunction with values contained in StartDly and EndDly. Start of transmission delay keeps RTS asserted for the time in StartDly (mS) before XXMIT sends a message out of PLC port. Likewise, end of transmission delay keeps RTS asserted for the time in EndDly (mS) after XXMIT has finished sending a message out of the PLC port. Once the end of transmission delay expires XXMIT de--assert RTS.

Set to 1 when the selected port should operate in RS485 mode. Otherwise it defaults to 0, which is RS232 mode. When using port 2 of a Momentum PLC in RS485 mode with Modbus Messaging, make sure to use exactly the same parameters (baudrate, databits, stopbits, parity) for the XXMIT block as configured for that port.

Reserved

Set to 1 to remove and discard all characters from FIFO until the starting string is matched, then these starting characters and subsequent characters are written into MsgIn until the terminator sequence is matched.

The terminator string is also written into the MsgIn. Refer to chapter

”Terminated ASCII Input Function” on page17 for more details.

Set to 1 to remove the ASCII characters from FIFO for writing into MsgIn array. Refer to chapter ”Simple ASCII Input Function” on page 20 for more details.

Set to 1 when you want to send ASCII messages out of the PLC. XXMIT sends ASCII strings up to 1024 characters in length. You program the

ASCII message into the MsgOut. Only use Bit 7 OR Bit 8, do not try to use both.

Set to 1 when you want to send Modbus messages out of the PLC.

Modbus messages may be in either RTU or ASCII formats. When data bits=8, XXMIT uses Modbus RTU format. When data bits=7, XXMIT uses Modbus ASCII format. Only use Bit 7 OR Bit 8, do not try to use both.

Set to 1 to allow the XXMIT block to take control over the selected port

(1 or 2) from the PLC. The block begins to receive ASCII characters into an empty 512 byte circular FIFO. Refer to chapter ”ASCII Receive

FIFO” on page 27 for more details.

Set to 1 to allow special handling of ASCII back space character (BS,

8Hex) when using either Simple ASCII Input (Bit 6) or Terminated ASCII

Input (Bit 5). If Bit 10 is set, each back space character will NOT be stored into MsgIn. Refer to chapter ”Enable Back space” on page 28 for more details.

Set to 1 to allow full duplex hardware flow control using the RTS and

CTS handshaking signals for ASCII massaging. The RTS/CTS operates in both the input and output modes. Refer to chapter ”Enable RTS/

CTS Flow Control” on page 28 for more details.

Set to 1 to allow full duplex software flow control using the ASCII Xon character (DC1, 11 Hex) and the ASCII Xoff character (DC3, 13 Hex).

The Xon/Xoff operates in both the input and output modes. Refer to chapter ”Enable Xon/Xoff Flow Control” on page 29 for more details.

XXMIT 11

Width: 185 mm

Height: 230 mm

Table 1 XXMIT Command Word Bit Definitions

Bit

Bit 13 Pulse dial modem

Bit 14 hangup modem

Bit 15 Tone dial modem

Bit 16 Initialize modem

Definition

Set to 1 when using a Hayes compatible dial--up modem and you wish to pulse dial a telephone number. You program the phone number into the MsgOut. The length of the message must be in MsgLen. Pulse dialed numbers are sent to the modem automatically preceded by ATDP and with carriage return <CR> and line feed <LF> appended. Since the dial message is an ASCII string, bit 7 must be ON prior to sending the number to be dialed.

Set to 1 when using a Hayes compatible dial--up modem and you want to hangup the modem. You must use user logic to turn this bit ON.

Since the hangup message is an ASCII string, bit 7 must be ON prior to sending the message. Hang up messages are sent to the modem automatically preceded by +++AT and with carriage return <CR> and line feed <LF> appended. XXMIT looks for a correct disconnect response from the modem before it turns ON the Done output signal, noting a successful completion.

Set to 1 when using a Hayes compatible dial--up modem and you wish to tone dial a telephone number. You program the phone number into the MsgOut. The length of the message must be in MsgLen. Tone dial numbers are sent to the modem automatically preceded by ATDT and with carriage return <CR> and line feed <LF> appended. Since the dial message is an ASCII string, bit 7 must be ON prior to sending the number to be dialed.

Set to 1 when using a Hayes compatible dial--up modem and you want to initialize the modem. You program the initialization message into

MsgOut and the length of the message into MsgLen. All messages are sent to the modem automatically preceded by AT and with a carriage return <CR> and line feed <LF> appended. Since the initialization message is an ASCII string, bit 7 must be ON prior to sending the message.

12 XXMIT

MsgOut

MsgOut contains the message data to be transferred, for example, ASCII characters for an ASCII transfer, definition of termination characters for terminated ASCII input or Modbus templates for Modbus master messages.

The data type that must be assigned to the parameter has to match the requirements of the function to be performed. The data type of the MsgOut parameter must be equal to the data type of the MsgIn field.

Note:

MsgOut and MsgIn are of Data Type ANY. It is preferrable to use a

Byte Array. Different from the XMIT Block, ASCII messages are stored in byte order, allowing for easy handling, for example, through assigning a string as an initial value.

Note:

For Modbus Messaging MsgOut must be a field of words. The minimum size of the array is WordArr9.

MsgLen

You must enter the length of the current message according to the selected

XXMIT function. The following table gives an overview for Modbus and ASCII functions:

XXMIT function

Modbus Messaging

Terminated ASCII Input

Simple ASCII Input

ASCII String Messaging

Subfunction Message Length

01, 02, 03, 04, 05, 06, 08, 15, 16 5

20, 21 6

1...1024.

1...1024. The selected length must match the size of the array assigned to MsgOut. Otherwise you get error 129.

Port

Port specifies the communications interface. The only authorized values are the values 1 and 2. Port 2 is only available on the Momentum PLC.

Baudrate

XXMIT supports the following data rates: 50, 75, 110, 134, 150, 300, 600, 1200,

1800, 2000, 2400, 3600, 4800, 7200, 9600, 19200. To configure a data rate, enter its decimal number. When an invalid data rate is entered, the block displays an illegal configuration error (error code 127) in the XXMIT Status element.

Databits

XXMIT supports the following data bits: 7 and 8. To configure a data bit size, enter its decimal number into this element. Modbus messages may be sent in

ASCII mode or RTU mode. ASCII mode requires 7 data bits, while RTU mode requires 8 data bits. When sending ASCII character message you may use either 7 or 8 data bits. When an invalid data bit is entered, the block displays an illegal configuration error (error code 127) in the XXMIT Status element. For more details on Modbus message formats refer to Modicon Modbus Protocol

Reference Guide

(PI MBUS 300).

Stopbits

XXMIT supports one or two stop bits. Enter a decimal of either: 1 = one stop bit, or 2 = two stop bits. When an invalid stop bit is entered, the block displays an illegal configuration error (error code 127) in the XXMIT Status element.

Parity

XXMIT supports the following parity: none, odd and even. Enter a decimal of either: 0 = no parity, 1 = odd parity, or 2 = even parity. When an invalid parity is entered, the block displays an illegal configuration error (error code 127) in the

XXMIT Status element.

XXMIT 13

Width: 185 mm

Height: 230 mm

14 XXMIT

RespTout

You enter the time value in milliseconds (mS) to determine how long XXMIT waits for a valid response message from a slave device (PLC, modem, etc.). In addition, the time applies to ASCII transmissions and flow control operations.

When the response message is not completely formed within this specified time,

XXMIT issues a fault. The valid range is 0 ... 65535 mS. The timeout is initiated after the last character in the message is sent.

RetryLmt

You enter the quantity of retries to determine how many times XXMIT sends a message to get a valid response from a slave device (PLC, modem, etc.).

When the response message is not completely formed within this specified time,

XXMIT issues a fault and a fault code. The valid range is 0 ... 65535 # of retries. This field is used in conjunction with RespTout.

StartDly

You enter the time value in milliseconds (mS) when RTS/CTS control is enabled, to determine how long XXMIT waits after CTS is received before it transmits a message out of the PLC port. Also, you may use this register even when RTS/CTS is NOT in control. In this situation, the entered time value determines how long XXMIT waits before it sends a message out of the PLC port. You may use this as a pre message delay timer. The valid range is

0 ... 65535 mS.

EndDly

You enter the time value in milliseconds (mS) when RTS/CTS control is enabled, to determine how long XXMIT keeps RTS asserted once the message is sent out of the PLC port. After the time expires, XXMIT deassert RTS. Also, you may use this register even when RTS/CTS is NOT in control. In this situation, the entered time value determines how long XXMIT waits after it sends a message out of the PLC port. You may use this as a post message delay timer. The valid range is 0 ... 65535 mS.

Retry

The value displayed here indicates the current number of retry attempts made by the XXMIT block. This element is read only.

Active

A value of 1 indicates that an XXMIT operation is in progress.

Done

A value of 1 indicates that the XXMIT operation has been completed successfully.

Error

A value of 1 indicates that an error has occurred or that the current XXMIT operation is terminated.

112

113

114

115

108

109

110

111

Fault Code

9 ... 99

100

101

102

103

104

105, 106

107

MsgIn

MsgIn contains the incoming message data, for terminated ASCII input or simple ASCII input.

The data type that must be assigned to the parameter has to match the requirements of the function to be performed. The data type must be equal to the type of the MsgOut field.

RecCount

This element displays the number of received characters.

Status

This element displays a fault code generated by the XXMIT block. A complete list is shown in the table below.

Table 2 Fault Status

Fault Description

Modbus exception -- Illegal function

Modbus exception -- Illegal data address

Modbus exception -- Illegal data value

Modbus exception -- Slave device failure

Modbus exception -- Acknowledge

Modbus exception -- Slave device busy

Modbus exception --Negative acknowledge

Modbus exception --Memory parity error

Reserved

Slave PLC data area cannot equal zero

Master PLC data area cannot equal zero

Coil (0x) not configured

Master PLC 4x Holding Register area not configured

Data length cannot equal zero

Reserved

Transmit message time--out (This error is generated when the UART cannot complete a transmission in 10 seconds or less. This error bypasses the retry counter and will activate the error output on the first error).

Undefined error

Modem returned ERROR

Modem returned NO CARRIER

Modem returned NO DIALTONE

Modem returned BUSY

Invalid LRC checksum from the slave PLC

Invalid CRC checksum from the slave PLC

Invalid Modbus function code

XXMIT 15

Width: 185 mm

Height: 230 mm

16 XXMIT

Table 2 Fault Status

Fault Code

120

121

122

123

116

117

118

119

124

125

126

131

132

133

134

127

128

129

130

135...149

150

151

152

153

Fault Description

Modbus response message time--out

Modem reply time--out

XXMIT could not gain access to PLC communications port #1 or port #2

XXMIT could not enable PLC port receiver

XXMIT could not set PLC UART

Reserved

Invalid Port

Reserved

Undefined internal state

Broadcast mode not allowed with this Modbus function code

DCE did not assert CTS

Illegal configuration (data rate, data bits, parity, or stop bits)

Unexpected response received from Modbus slave

Illegal command word setting

Command word changed while active

Invalid character count

Reserved

ASCII input FIFO overflow error

Invalid number of start characters or termination characters

Reserved

Either configured port already taken by another instance of the XXMIT or the configured port is not supported on that PLC

MsgOut is smaller than 12 Byte while ’Modbus Master Messaging’ function is selected

Variable connected to MsgOut is smaller than the value of the MsgLen parameter while ’ASCII String Messaging’ is selected

Variable connected to MsgIn is smaller than the value of the MsgLen parameter while either ’Terminated ASCII Input’ or ’SimpleASCII Input’ is selected

4 XXMIT Communication Functions

The XXMIT communication block performs six functions shown below. For each function certain bits of the Command word must be set.

Table 3 Command Word Functions in Relation to Bits

Function Command word bits that may be set to 1

Bits that MUST be set to =

Terminated ASCII input (Bit

5=1) *

Simple ASCII input (Bit 6=1) *

Simple ASCII output (Bit 7=1)

2,3,9,10,11,12

6,7,8,13,14,15,16

5,7,8,13,14,15,16

5,6,8,13,14,15,16

Modem output (Bit 7=1) 2,3,13,14,15,16

Modbus master messaging output (Bit 8=1)

2,3 5,6,7,9,10,11,12,13,14,15,16

* When using either of these functions you MUST set Enable ASCII receive FIFO ( Bit 9) to 1.

Bit 1 (MSB) and Bit 4 are reserved. (See Table 1)

5,6,8,9,10,11,12 (plus one, but ONLY one, of the following bits is set to 1: 13,14,15 or 16, while the other three bits must be set to 0)

4.1

Terminated ASCII Input Function

When Bit 5 of the Command Word is activated for terminated ASCII Input messages, the MsgOut array has to contain the ASCII input definition table.

Depending of which datatype you selected for MsgOut, the terminated ASCII definition table consists of three words or 6 byte. The terminated ASCII input definition table is shown in the table below.

Table 4 Terminated ASCII Input Definition Table (Datatype WordArray)

Word

MsgOut[1]

MsgOut[2]

MsgOut[3]

High Byte

Number of starting characters (allowed content = 0, 1, 2)

First starting character

First terminator character

Low Byte

Number of terminator characters

(allowed content = 1, 2)

Second starting character

Second terminator character

XXMIT 17

Width: 185 mm

Height: 230 mm

18 XXMIT

Table 5 Terminated ASCII Input Definition Table (Datatype ByteArray)

Byte

MsgOut[1]

MsgOut[2]

MsgOut[3]

MsgOut[4]

MsgOut[5]

MsgOut[6]

Function

length of termination string (1 or 2) length of start string (0 or 1 or 2)

2nd start character

1st start character

2nd termination character

1st termination character

During the process, RecCount holds a running count of characters written into the MsgIn array. Once the terminated string is received the Done output on the

XXMIT block goes ON and RecCount holds the total length of the received string including the starting and terminator strings. At this point the XXMIT block still owns the port and continues to save newly received characters into the ASCII receive FIFO, because the enable ASCII receive FIFO Command

Word, Bit 9 is ON.

Using program logic, you can clear the simple ASCII input Bit before the next scan, while leaving the enable ASCII receive FIFO Bit ON. Thus, MsgIn is

NOT over written by newer FIFO data, which is still collected in the FIFO. Using program logic, you can clear both bits for enable ASCII receive FIFO ( Bit 9), and terminated ASCII input (Bit 5) to return port control back to the PLC.

When too many characters are written into the MsgIn array with NO terminator detected, or the MsgIn array is outside the allowed range for the configured PLC an error is reported in Status. The character limit is the smaller of 1024 or two times the sizes of the MsgIn array.

Terminated ASCII Example

Assume that XXMIT is activated with the command word Bit 9 and 5 set.

Enable ASCII FIFO and terminated ASCII. The following ASCII string is received by the port: “AMScrlf$weight = 1245 GRAMScrlf$wei”. Refer to the

ASCII Input Definition Table that shows the contents denoted by ( ) used in this example.

Table 6 Terminated ASCII Input Definition Table (content Datatype Byte Array)

Byte

MsgOut[1]

MsgOut[2]

MsgOut[3]

MsgOut[4]

MsgOut[5]

MsgOut[6]

Content

Number of starting characters (0x01)

Number of terminator characters (0x02)

Second starting character (Not Used)

First starting character (’$’)

Second terminator character (’lf’’)

First terminator character (’cr’)

Table 7 Terminated ASCII Input Definition Table Example (content for Datatype Word

Array)

Word

MsgOut[1]

MsgOut[2]

MsgOut[3]

High Byte

Number of starting characters

(0x01)

First starting character (’$’)

First terminator character (’cr’)

Low Byte

Number of terminator characters

(0x02)

Second starting character (Not

Used)

Second terminator character (’lf’’)

The XXMIT block becomes ACTIVE and then discards from the input FIFO the initial five characters, “AMScrlf”, because they do not match the first starting character set to ’$’. On the logic scan after the ’$’ is received, the XXMIT block remains ACTIVE and it copies the ’$’ and subsequent characters into the MsgIn array, updating RecCount with the count done so far, as the characters come in.

After the final termination character is received the output Done is activated and

MsgLen contains the total length equal to 22 characters (0x0016). The MsgIn array contains: “$weight = 1245 GRAMScrlf” as Byte Array (or: “$w”, “ei”, “gh”,

“t ”, “= ”, “12”, “45”, “ G”, “RA”, “MS”, “crlf” if using a Word Array). On the scan that the output Done is activated, the already received characters from the next message, “$wei”, that came in after the termination string, remains in the ASCII input FIFO. This gives the program logic the opportunity to turn off the

Terminated ASCII input before the next scan solve of XXMIT for this port, keeping those characters in the FIFO until the PLC completes processing the current message, that might take several scans.

XXMIT 19

Width: 185 mm

Height: 230 mm

20 XXMIT

4.2

Simple ASCII Input Function

All incoming characters are placed into the MsgIn array. If MsgIn is defined as

WordArray, two characters are stored in each element. The first character transferred from FIFO is stored in the high byte of the first element. The second character is transferred from FIFO is stored in the low byte of the first element.

The third character is stored in the high byte of the second element, and so on.

The Message Length variable (MsgLen) contains the length of the message

(1 ... 1024 characters).

Note:

When Simple ASCII Input (Bit 6) and ASCII Receive FIFO (Bit 9) remain set, new characters are continuously transferred from FIFO into the same MsgIn array thus constantly over writing the previous characters stored into the MsgIn array.

4.3

ASCII String Messaging

When Command Word, Bit 7 is activated for String Messaging, the MsgOut array has to contain the ASCII information to be transmitted. The message length MsgLen has to be set to the length of the message to be transmitted.

As mentioned in the Chapter 3.2 Parameter description, MsgOut may be of any datatype. For ASCII String Messaging the type ByteArray reflects best the nature of strings: First Byte contains first character and so on. (See Examples

Table 19)

4.4

Modem Output

The XXMIT function block allows you to communicate to a Hayes compatible modem using the functions listed in the following table:

Table 7 Modem Functions

Bit in Command Word

Bit 13

Bit 14

Bit 15

Bit 16

Function

Pulse dial modem

Hangup modem

Tone dial modem

Initialize modem

Initialize Modem

Set Bit 16 of the command word to 1 when using a Hayes compatible dial--up modem and you want to initialize the modem. You program the initialization message into the MsgOut array and the length of the message into MsgLen. All messages are sent to the modem automatically preceded by AT and with a carriage return <CR> and line feed <LF> appended. Since the initialization message is an ASCII string, bit 7 must be ON prior to sending the message.

Pulse Dial Modem

Set Bit 13 of the command word to 1 when using a Hayes compatible dial--up modem and you wish to pulse dial a telephone number. You program the phone number into the MsgOut array. The length of the message must be in MsgLen.

Pulse dialed numbers are sent to the modem automatically preceded by ATDP and with carriage return <CR> and line feed <LF> appended. Since the dial message is an ASCII string, bit 7 must be ON prior to sending the number to be dialed.

Tone Dial Modem

Set Bit 15 of the command word to 1 when using a Hayes compatible dial--up modem and you wish to tone dial a telephone number. You program the phone number into the MsgOut array. The length of the message must be in MsgLen.

Tone dialed numbers are sent to the modem automatically preceded by ATDT and with carriage return <CR> and line feed <LF> appended. Since the dial message is an ASCII string, bit 7 must be ON prior to sending the number to be dialed.

XXMIT 21

Width: 185 mm

Height: 230 mm

22 XXMIT

Hangup Modem

Set Bit 14 of the command word to 1 when using a Hayes compatible dial--up modem if you want to hangup the modem. You must use program logic to turn this bit ON. Since the hangup message is an ASCII string, bit 7 must be ON prior to sending the message. Hang up messages are sent to the modem automatically preceded by +++AT and with carriage return <CR> and line feed

<LF> appended. XXMIT looks for a correct disconnect response from the modem before it turns ON the Done output signal, noting a successful completion.

4.5

Modbus Messaging

Note:

When using port 2 of a Momentum PLC in RS485 mode with Modbus

Messaging, make sure to use exactly the same parameters (baudrate, databits, stopbits, paritty) for the XXMIT block as configured for that port.

Modbus Function Codes (01 ... 06, 15 and 16)

For Modbus messages, the MsgOut array has to contain the Modbus definition table. This has to be defined as a field of words. The Modbus definition table for

Modbus function code: 01, 02, 03, 04, 05, 06, 15 and 16 is five registers long and you must set MsgLen to 5 for successful XXMIT operation. The Modbus definition table is shown in the table below.

Table 8 Modbus Definition Table Function Codes (01 ... 06, 15 and 16)

Content

Master PLC data area

(MsgOut[5])

Description

Modbus function code

(MsgOut[1])

Quantity (MsgOut[2])

XXMIT supports the following function codes:

01 = Read multiple coils (0x)

02 = Read multiple discrete inputs (1x)

03 = Read multiple holding registers (4x)

04= Read multiple input registers (3x)

05 = Write single coil (0x)

06 = Write single holding registers (4x)

15 = Write multiple coils (0x)

16 = Write multiple holding registers (4x)

Enter the amount of data you want written to the slave PLC or read from the slave PLC. For example, enter 100 to read

100 holding registers from the slave PLC or enter 32 to write

32 coils to a slave PLC. There is a size limitation on quantity that is dependent on the PLC model. Refer to Appendix

A for complete details on limits.

Slave PLC address (MsgOut[3]) Enter the slave Modbus PLC address. Typically the Modbus address range is 1 ... 247. To send a Modbus message to multiple PLCs, enter 0 for the slave PLC address. This is referred to as Broadcast Mode. Broadcast Mode only supports Modbus function codes that writes data from the master PLC to slave PLCs. Broadcast Mode does NOT support

Modbus function codes that read data from slave PLCs.

Slave PLC data area

(MsgOut[4])

For a read command, the slave PLC data area is the source of the data. For a write command, the slave PLC data area is the destination for the data. For example, when you want to read coils (00300 ... 00500) from a slave PLC, enter 300 in this field. When you want to write data from a master

PLC and place it into register (40100) of a slave PLC, enter

100 in this field. Depending on the type of Modbus command (write or read), the source and destination data areas must be as defined in the Source and Destination Data

Areas table below.

For a read command, the master PLC data area is the destination for the data returned by the slave. For a write command, the master PLC data area is the source of the data.

For example, when you want to write coils (00016 ... 00032) located in the master PLC to a slave PLC, enter 16 in the field. When you want to read input registers

(30001 ... 30100) from a slave PLC and place the data into the master PLC data area (40100 ... 40199), enter 100 in this field. Depending on the type of Modbus command

(write or read), the source and destination data areas must be as defined in the Source and Destination Data Areas table below.

XXMIT 23

Width: 185 mm

Height: 230 mm

24 XXMIT

Table 9 Source and Destination Data Areas for Function Codes (01 ... 06, 15 and 16)

Function Code

03 (Read multiple 4x)

04 (Read multiple 3x)

01 (Read multiple 0x)

02 (Read multiple 1x)

16 (Write multiple 4x)

15 (Write multiple 0x)

05 (Write single 0x)

06 (Write single 4x)

Master PLC Data Area

4x (destination)

0x (destination)

4x (source)

0x (source)

4x (source)

Slave PLC Data Area

4x (source)

3x (source)

0x (source)

1x (source)

4x (destination)

0x (destination)

4x (destination)

When you want to send 20 Modbus messages out of the PLC, you must transfer

20 Modbus definition tables one after another into MsgOut after each successful operation of XXMIT, or you may program 20 separate XXMIT blocks and then activate them one at a time through user logic.

Modbus Function Code (08)

For Modbus messages, the MsgOut array has to contain the Modbus definition table. This has to be defined as a field of words. The Modbus definition table for

Modbus function code: 08 is five registers long and you must set MsgLen to 5 for successful XXMIT operation. The Modbus definition table is shown in the table below.

Table 10 Modbus Definition Table Function Codes (08)

Content

Modbus function code

(MsgOut[1])

Diagnostics (MsgOut[2])

Slave PLC address

(MsgOut[3])

Diagnostics function data field content (MsgOut[4])

Master PLC data area

(MsgOut[5])

Description

XXMIT supports the following function code:

08 = Diagnostics

Enter the diagnostics subfunction code decimal value in this field to perform the specific diagnostics function desired.

The following diagnostic subfunctions are supported:

Code

Description

Return query data

Restart comm option

Return diagnostic register

Change ASCII input delimiter

Force listen only mode

05 ... 09 Reserved

Clear counters (& diagnostics registers in 384, 484)

Return bus messages count

Return bus comm error count

13 Return bus exception error count

14 ... 15 Not supported

Return slave NAK count

Return slave busy count

Return bus Char overrun count

19 ... 21 Not supported

Enter the slave Modbus PLC address. Typically the Modbus address range is 1 ... 247. Function code 8 does NOT support Broadcast Mode (Address 0)

You must enter the decimal value needed for the data area of the specific diagnostic subfunction. For subfunctions 02, 04,

10, 11, 12, 13, 16, 17 and 18 this value is automatically set to zero. For subfunctions 00, 01, and 03 you must enter the desired data field value. For more details, refer to Modicon

Modbus Protocol Reference Guide (PI--MBUS--300)

For all subfunctions, the master PLC data area is the destination for the data returned by the slave. You must specify a 4x register that marks the beginning of the data area where the returned data is placed. For example, to place the data into the master PLC data area starting at (40100), enter 100 in this field. Subfunction 04 does NOT return a response.

For more details, refer to Modicon Modbus Protocol Refer-

ence Guide (PI--MBUS--300)

XXMIT 25

Width: 185 mm

Height: 230 mm

26 XXMIT

Modbus Function Codes (20, 21)

For Modbus messages, the MsgOut array has to contain the Modbus definition table. This has to be defined as a field of words. The Modbus definition table for

Modbus function codes: 20 and 21 is six registers long and you must set

MsgLen to 6 for successful XXMIT operation. The Modbus definition table is shown in the table below.

Table 11 Modbus Definition Table Function Codes (20, 21)

Content

Modbus function code

(MsgOut[1])

Quantity (MsgOut[2])

Slave PLC address

(MsgOut[3])

Slave PLC data area

(MsgOut[4])

Master PLC data area

(MsgOut[5])

File number (MsgOut[6])

Description

XXMIT supports the following function codes:

20 = Read general reference (6x)

21 = Write general reference (6x)

Enter the amount of data you want written to the slave PLC or read from the slave PLC. For example, enter 100 to read

100 holding registers from the slave PLC or enter 32 to write

32 coils to a slave PLC. There is a size limitation on quantity that is dependent on the PLC model.

Enter the slave Modbus PLC address. Typically the Modbus address range is 1 ... 247. Function code 20 and 21 do NOT support Broadcast Mode (Address 0).

For a read command, the slave PLC data area is the source of the data. For a write command, the slave PLC data area is the destination for the data. For example, when you want to read registers (600300 ... 600399) from a slave PLC, enter

300 in this field. When you want to write data from a master

PLC and place it into register (600100) of a slave PLC, enter

100 in this field. Depending on the type of Modbus command (write or read), the source and destination data areas must be as defined in the Source and Destination Data

Areas table below. The lowest extended register is addressed as register ”zero” (600000). The lowest holding register is addressed as register ”one” (400001).

For a read command, the master PLC data area is the destination for the data returned by the slave. For a write command, the master PLC data area is the source of the data.

For example, when you want to write registers

(40016 ... 40032) located in the master PLC to 6x registers in a slave PLC, enter 16 in the field. When you want to read

6x registers (600001 ... 600100) from a slave PLC and place the data into the master PLC data area (40100 ... 40199), enter 100 in this field. Depending on the type of Modbus command (write or read), the source and destination data areas must be as defined in the Source and Destination

Data Areas table below. The lowest extended register is addressed as register ”zero” (600000). The lowest holding register is addressed as register ”one” (400001).

Enter the file number for the 6x registers to be written to or read from. (1 ... 10) depending on the size of the extended register data area. 600001 is 60001 file 1 and 69 0001 is

60001 file 10 as viewed by the Reference Data Editor.

Table 12 Source and Destination Data Areas for Function Codes (20, 21)

Function Code

20 (Read general reference

6x)

21 (Write general reference

6x)

Master PLC Data Area

4x (destination)

4x (source)

Slave PLC Data Area

6x (source)

6x (destination)

When you want to send 20 Modbus messages out of the PLC, you must transfer

4.6

ASCII Receive FIFO

Setting Bit 9 of the command word to 0 ends this function. When the FIFO receives 512 characters an internal overflow is set. When this occurs all subsequent characters are discarded, all ASCII input operations (simple and terminated) are ended, and the block returns an error until you toggle (Bit 9).

When (Bit 9) is toggled, all data in the FIFO is discarded, both ASCII input control bits are ignored (Simple ASCII (Bit 6), Terminated ASCII (Bit 5)), and when no ASCII output controls are selected then the control of the serial port (1 or 2) is returned back to the PLC.

You need to set either Terminated ASCII (Bit 5) or Simple ASCII (Bit 6) to remove the ASCII characters from FIFO for processing. No more than one of the following three bits can be set simultaneously: Terminated ASCII (Bit 5),

Simple ASCII (Bit 6), or ASCII Output (Bit 7).

Full duplex operation may be achieved by setting both ASCII Receive FIFO (BIT

9), and ASCII Output (Bit 7). This allows simple ASCII transmission out of the

PLC while still receiving ASCII characters into FIFO. This is useful when working with dumb terminals. When ASCII Receive FIFO (Bit 9) is set none of the following ASCII output controls are allowed: Modbus Master Messaging (Bit

8), Pulse Dial Modem (Bit 13), Hangup Modem (Bit 14), Tone Dial Modem (Bit

15) and Initialize Modem (Bit 16).

XXMIT 27

Width: 185 mm

Height: 230 mm

28 XXMIT

4.7

Back space and Flow Control

Enable Back space

When a backspace (BS) is detected it is NOT stored into the MsgIn array, in fact it deletes the previous character and thus decreases the RecCount Character

Counter. In contrast, when a regular ASCII character is detected it is stored in the MsgIn array and the RecCount Character Counter is increased.

Note:

Back spaces CANNOT delete characters from an empty MsgIn array, thus the RecCount Character Counter never goes below 0.

This special back space functionality along with internal echo enabled at the terminal are very useful for dealing with dumb terminals. A single Terminated

ASCII Input XXMIT block searching for “cr” is activated with ASCII Receive

FIFO (Bit 9) and back space (Bit 10) set. No additional program logic is required while you type and edit characters using the back space on the fly.

When you type “cr” XXMIT activates the Done output, and the corrected data is all lined up properly in the MsgIn array.

Enable RTS/CTS Flow Control

The following pertains to the output mode. The XXMIT state goes to BLOCKED receiving when the receiving device indicates it cannot process additional characters by setting CTS to OFF. Likewise, The XXMIT state goes to

UNBLOCKED when CTS is ON and the receiving devices indicates it CAN process additional characters.

When transmission is UNBLOCKED and Simple ASCII Output (Bit 7) and

RTS/CTS Flow Control (Bit 11) are set then the transmit output data is sent out in 16 byte packets. After all output packets are sent then the Done output on the XXMIT block goes ON to indicate “Operation Successful”.

CTS in ON will the ASCII output resume sending all remaining output packets.

The following pertains to the input mode. Since RTS is an output signal, it can be used independently of the ASCII output transmit process, to BLOCK or

UNBLOCK sending devices. When ASCII Receive FIFO (Bit 9) is set the

RTS/CTS Flow Control works in the input mode. When ASCII Receive FIFO

(Bit 9) is set and neither of the two ASCII inputs are set, Simple ASCII Input (Bit

6) or Terminated ASCII Input (Bit 5), the received characters will fill the FIFO in which they are inserted. In the mean time, the RTS Flow Control (Bit 11) is ON allowing the sending device to proceed.

When the FIFO (512 characters) is more than three quarters full with characters the RTS Control Flow (Bit 11) is cleared to BLOCK the sending device. The

RTS Control Flow (Bit 11) remains cleared until either Simple ASCII Input (Bit 6) or Terminated ASCII Input (Bit 5) have removed enough characters from the

FIFO whereby reducing it to less than one quarter full of characters at which point the RTS Control Flow (Bit 11) is turned ON.

Note:

The RTS/CTS Flow Control algorithm is different from RTS/CTS

Modem Control. The former is related to full duplex receive buffer overflow.

The latter deals with the transmit process gaining access to a shared transmission medium. Therefore, it is illegal to simultaneously request both of these RTS/CTS algorithms.

Note:

You CANNOT select any type of RTS/CTS Flow Control (Bit 11) handshaking when the port is in RS 485 Mode (Bit 3) because these signals do

NOT exist in RS 485 mode.

Enable Xon/Xoff Flow Control

The following pertains to the output mode. The XXMIT state goes to BLOCKED when an Xoff character is received. Likewise the XXMIT state goes to

UNBLOCKED when an Xon character is received. In neither case will Xon or

Xoff be inserted into the FIFO.

When transmission is UNBLOCKED and Simple ASCII Output (Bit 7) and

Xon/Xoff Flow Control (Bit 12) are set then the transmit output data is sent out in

16 byte packets. After all output packets are sent the Done output on the

XXMIT block goes ON.

If during a transmission it suddenly becomes BLOCKED, only the remaining characters in the current output packet are sent, never exceeding 16 characters, and the XXMIT block remains ACTIVE indefinitely. Only when the next Xon character is received will the ASCII output resume sending all remaining output packets.

XXMIT 29

Width: 185 mm

Height: 230 mm

30 XXMIT

The following pertains to the input mode. Xon/Xoff may be used to BLOCK or

UNBLOCK sending devices. When ASCII Receive FIFO (Bit 9) is set the

Xon/Xoff Control Flow (Bit 12) works in the input mode. When ASCII Receive

FIFO (Bit 9) is set and neither of the two ASCII inputs are set, Simple ASCII

Input (Bit 6) or Terminated ASCII Input (Bit 5), the received characters will fill the

FIFO in which they are inserted.

When the FIFO is more than three quarter full with characters and additional characters are received the FIFO state variable is set to send XOFF characters out the serial port after a delay of up to 16 character times BLOCKING the sender and clearing the FIFO state variable.

When all ASCII output functions (Bits 8,13,14,15, and 16) are OFF and the

Xon/Xoff Flow Control (Bit 12) is ON the delay time defaults to 1 character time.

In contrast, when all ASCII output functions (Bits 8,13,14,15, and 16) are ON and the Xon/Xoff Flow Control (Bit 12) is ON then the ASCII output is broken up into 16 byte packets. Thus, pending Xoff characters DO NOT have to wait more than 16 character times before BLOCKING the sender.

Once the sender has stopped transmission, the PLC eventually removes the characters from the FIFO using either Simple ASCII Input (Bit 6) or Terminated

ASCII Input (Bit 7).

When FIFO becomes less than one quarter full with characters the FIFO state variable is set to send XON, thus, sending an Xon character out the serial port to UNBLOCK the sender.

Note:

To prevent lockup due to a disconnected cable or other intermittent communication errors, when the sender is BLOCKED and did NOT receive the

Xon character correctly we use the following algorithm. When FIFO becomes empty and no characters are subsequently received, then a steady stream of

Xon characters are transmitted at the rate of once every 5 seconds.

Note:

The Xon/Xoff Flow Control (Bit 12) is different from the RTS/CTS

Control Flow (Bit 11). The former uses transmitted Xon and Xoff characters to prevent receive buffer overflow in full duplex mode. The latter uses hardware hand--shaking signals to accomplish the same goal. Therefore, it is illegal to simultaneously request both of these flow control algorithms because RTS/CTS

Flow Control (Bit 11) Modem Control implies a half duplex network while

Xon/Xoff Flow Control (Bit 12) implies a full duplex network.

Width: 185 mm

Height: 230 mm

5 Run Time Errors

In case of error, the XXMIT function block will generate the following runtime error:

E_EFB_WORLD_INTERFACE

This will be displayed in the Online Event dialog.

Subject to the value of the first error message parameter, the error message will have various origins.

An invalid communications interface was selected.

An invalid value for the communications interface was selected at the Port input. Authorized values are ”1” and ”2” for Momentum PLCs, all other platforms only “1”.

Selected port is already taken by another instance of XXMIT.

Either an invalid value for Baudrate/Stopbits/Databits has been used or the variables connected to MsgIn or MsgOut do not provide enough memory for the configured XXMIT operation.

XXMIT 31

32 XXMIT

6 Application Example

6.1

Description

The following program is a short demo application with four instances of the

XXMIT block showing the four main functions:

Modbus Master

Simple ASCII In

ASCII Message Out

Terminated ASCII In

6.2

Modbus Master

The following Modbus Master operation is a read request to a slave device connected to port 1 of the master:

Read slave’s 4:0001 to 4:00010 into local 4:00011 to 4:00020

The Slave must be set up with the following port parameters:

9600 baud

8 data bits

1 stop bit even parity (2)

The Master uses settings from the XXMIT function block

Width: 185 mm

Height: 230 mm

Variable declaration

The following table shows the variables used in the Modbus Master example

Table 13 Variable table

Variable Name

StartModbusMstr

ModbusMstrActive

ModbusMstrCommand

ModbusMstrDone

ModbusMstrError

ModbusMstrNode

ModbusMstrSettings

ModbusMstrSettings[1]

ModbusMstrSettings[2]

ModbusMstrSettings[3]

ModbusMstrSettings[4]

ModbusMstrSettings[5]

ModbusMstrSettings[6]

...

ModbusMstrStatus

ModbusMstrNode

ModbusMstrErrorCounter

ModbusMstrDoneCounter

Data

Type

BOOL

WORD

BOOL

WORD

WordArr9

Initial

Value

Comment

16#0100 Bit 8 set

Modbus Code: Read multiple registers

Amount of Registers to read

Slave Modbus address

Source register

Destination Register not used

INT

WORD

INT

Enter Slave address

XXMIT 33

34 XXMIT

IEC Section

Program the following in an FBD section:

MOVE

ModbusMstrNode

Slave node address assignment

ModbusMstrSettings[3]

StartModbusMstr

ModbusMstrCommand

ModbusMstrSettings

9600

1000

100

XXMIT

Start

Command

MsgOut

MsgLen

Port

Baudrate

Databits

Stopbits

Parity

RespTout

RetryLmt

StartDly

EndDly

Active

Done

Error

MsgIn

RecCount

Status

Retry

ModbusMstrActive

ModbusMstrDone

ModbusMstrError

ModbusMstrStatus

ModbusMstrRetryCounter

ModbusMstrError

CTU

ModbusMstrDone

CTU

Count errors and successes

ModbusMstrErrorCounter

ModbusMstrDoneCounter

Width: 185 mm

Height: 230 mm

6.3

Simple ASCII Receive

Receives whatever comes into port 1. The receive buffer’s length is assigned as

’SimpleReceiveLength’, which has an initial value of 10.

Received characters are in MsgIn array, number of received characters in

RecCount.

Variable declaration

The following table shows the variables used in the Simple ASCII Receive example

Table 14 Variable table

Variable Name

StartSimpleReceive

Data

Type

BOOL

SimpleReceiveActive BOOL

SimpleReceiveCharCounter INT

SimpleReceiveCommand

SimpleReceiveDone

WORD

BOOL

SimpleReceiveError

SimpleReceiveLength

BOOL

INT

SimpleReceiveRetryCounter INT

SimpleReceiveStatus INT

SimpleRecMessage ByteArr12

SimpleReceiveDoneCounter INT

SimpleReceiveErrorCounter INT

Initial

Value

Comment

16#0480 Bits 6 and 9 set. FIFO enabled

XXMIT 35

36 XXMIT

IEC Section

Program the following in an FBD section:

StartSimple Receive

SimpleReceiveCommand

SimpleReceiveLength

9600

1000

100

XXMIT

Start

Command

MsgOut

MsgLen

Port

Baudrate

Databits

Stopbits

Parity

RespTout

RetryLmt

StartDly

EndDly

Active

Done

Error

MsgIn

RecCount

Status

Retry

SimpleReceiveActive

SimpleReceiveDone

SimpleReceiveError

SimpleRecMessage

SimpleReceiveCharCount

SimpleReceiveStatus

SimpleReceiveRetryCounter

SimpleReceiveError

CTU

SimpleReceiveDone

CTU

Count errors and successes

SimpleReceiveErrorCounter

SimpleReceiveDoneCounter

Width: 185 mm

Height: 230 mm

6.4

Simple ASCII Send

Sends a simple ASCII message out off port 1, the message is ’Hello World!!’

Variable declaration

The following table shows the variables used in the Simple ASCII Send example

Table 15 Variable table

Variable Name

StartSimpleSend

SimpleSendActive

SimpleSendCommand

SimpleSendDone

SimpleSendError

SimpleSendLength

SimpleSendMessage

SimpleSendMessage[1]

SimpleSendMessage[2]

SimpleSendMessage[3]

SimpleSendMessage[4]

SimpleSendMessage[5]

SimpleSendMessage[6]

SimpleSendMessage[7]

SimpleSendMessage[8]

SimpleSendMessage[9]

SimpleSendMessage[10]

SimpleSendMessage[11]

SimpleSendMessage[12]

SimpleSendMessage[13]

SimpleSendMessage[14]

SimpleSendRetryCounter

SimpleSendStatus

SimpleSendDoneCounter

SimpleSendErrorCounter

INT

Data

Type

BOOL

WORD

BOOL

INT

ByteArr36

Initial

Value

16#48

16#65

16#6C

16#6F

16#20

16#57

16#6F

16#72

16#6C

16#64

16#20

16#21

Comment

16#0200 Bit 7 set

Number of characters to send

’Hello World !!’

XXMIT 37

38 XXMIT

IEC Section

Program the following in an FBD section:

StartSimpleSend

SimpleSendCommand

SimpleSendMessage

SimpleSendLength

9600

1000

100

XXMIT

Start

Command

MsgOut

MsgLen

Port

Baudrate

Databits

Stopbits

Parity

RespTout

RetryLmt

StartDly

EndDly

Active

Done

Error

MsgIn

RecCount

Status

Retry

SimpleSendActive

SimpleSendDone

SimpleSendError

SimpleSendStatus

SimpleSendRetryCounter

SimpleSendError

CTU

SimpleSendDone

CTU

Count errors and successes

SimpleSendErrorCounter

SimpleSendDoneCounter

Width: 185 mm

Height: 230 mm

6.5

Terminated ASCII Receive

After receiving the ’starting characters’ ”AB”, the function block puts all received characters into the receive buffer MsgIn. The receiver will stop when the

’finishing characters’ ”CD” are received, whereby the ”Done” output will be set, to indicate the successfull completion. The max. length of the receive buffer is assigned as ”TermReceiveLength”, which is set to an initial value of 20 in this example.

Variable declaration

The following table shows the variables used in this example

Table 16 Variable table

Variable Name

StartTermReceive

TermReceiveActive

TermReceiveCharCounter

TermReceiveCommand

TermReceiveDone

TermReceiveError

TermReceiveLength

TermReceiveMessage

TermReceiveRetryCounter

TermReceiveSettings

TermReceiveSettings[1]

TermReceiveSettings[2]

TermReceiveSettings[3]

TermReceiveSettings[4]

TermReceiveSettings[5]

TermReceiveSettings[6]

TermReceiveStatus

TermReceiveDoneCounter

TermReceiveErrorCounter

Data

Type

BOOL

INT

WORD

BOOL

INT

ByteArr36

INT

ByteArr36

Initial

Value

16#0880 Bits 5 and 9 set. FIFO enabled

16#02

16#41

16#42

16#43

16#44

Comment

Received characters length of termination string (1 or 2) length of start string (0, 1 or 2)

2nd start character

1st start character

2nd termination character

1st termination character

INT

XXMIT 39

40 XXMIT

IEC Section

Program the following in an FBD section:

StartTermReceive

TermReceiveCommand

TermReceiveSettings

TermReceiveLength

9600

1000

100

XXMIT

Start

Command

MsgOut

MsgLen

Port

Baudrate

Databits

Stopbits

Parity

RespTout

RetryLmt

StartDly

EndDly

Active

Done

Error

MsgIn

RecCount

Status

Retry

TermReceiveActive

TermReceiveDone

TermReceiveError

TermReceiveMessage

TermReceiveCharCounter

TermReceiveStatus

TermReceiveRetryCounter

TermReceiveError

CTU

TermReceiveDone

CTU

Count errors and successes

TermReceiveErrorCounter

TermReceiveDoneCounter

6.6

Entering Strings as initial values

The Variable Editor of Concept allows you to easily enter Strings as initial values into byte arrays.

The following part gives a short describtion of how to define a variable

’DemoString’ as ’ByteArr36’ and enter a string ’My Text ! ’ as initial value.

Open the Variable Editor

From the main menu select Project ® Variable Editor.

Figure 2 Variable Editor

Define new variable

Enter the new variables name in the ’Variable Name’ field. As data type select

’ByteArrxx’ (xx depends on the size of your message). In the ’InitValue’ field a

’Set...’ button appears.

Enter text as initial value

Click on the ’Set...’ button and open the definition window. Double clicking into the value field brings up a cursor and allows you to enter your text.

XXMIT 41

Width: 185 mm

Height: 230 mm

42 XXMIT

Figure 3 Definition ByteArr

Look at Array Elements

Click on the ’+’ button in front of the variables name and open the view onto all array elements. The value column shows the ASCII code representation of the entered characters as hexadecimal numbers.

Figure 4 Elements of the Byte Array

Width: 185 mm

Height: 230 mm

XXMIT 43

7 Technical References

The following chapter contains information about:

Modbus Query/Response Parameter Limits

Cable Pinouts

Cable Adapter Kits

XMIT Configuration using Hayes Compatible Dialup Modems (Only)

44 XXMIT

Width: 185 mm

Height: 230 mm

7.1

Modbus Query/Response Parameter Limits

The query/response parameters are limited based upon the type of PLC you are using. Refer to the applicable table below.

884/Quantum PLC Maximum Parameters

584/984 PLC Maximum Parameters

484 PLC Maximum Parameters

184/384 PLC Maximum Parameters

M84 PLC Maximum Parameters

Table 17 Quantum PLC Maximum Parameters

Function

Code

Description Query

Read Coil Status

Read Input Status

2000 Coils

2000 Inputs

Read Holding Registers 125 Registers

Read Input Registers 125 Registers

Force Single Coil

Force Single Register

Force Multiple Coil

Force Multiple Register

Read General References

1 Coil

1 Register

800 Coils

100 Registers

Maximum length of the entire message can

NOT exceed 256 bytes

Write General References

Maximum length of the entire message can

NOT exceed 256 bytes

Response

2000 Coils

2000 Inputs

125 Registers

1 Coil

1 Register

800 Coils

100 Registers

Maximum length of the entire message can NOT exceed 256 bytes

Note:

The 140 CPU 113 02 and the 140 CPU 113 03 do not support

Gerneral References.

XXMIT 45

46 XXMIT

Table 18 884 PLC Maximum Parameters

Function

Code

Description

Read Coil Status

Read Input Status

Read Holding Registers

Read Input Registers

Force Single Coil

Force Single Register

Force Multiple Coil

Force Multiple Register

Read General References

Write General References

Response

2000 Coils

2000 Inputs

125 Registers

1 Coil

1 Register

800 Coils

100 Registers

NOT Supported

Table 19 584/984 PLC Maximum Parameters

Function

Code

Description

Read Coil Status

Read Input Status

Read Holding Registers

Read Input Registers

Force Single Coil

Force Single Register

Force Multiple Coil

Force Multiple Register

Read General References (6x)

Write General References (6x)

Response

2000 Coils

2000 Inputs

125 Registers

1 Coil

1 Register

800 Coils

100 Registers

Maximum length of the entire message can

NOT exceed 256 bytes

Maximum length of the entire message can

NOT exceed 256 bytes

Width: 185 mm

Height: 230 mm

Table 20 484 PLC Maximum Parameters

Function

Code

Description

Read Coil Status

Read Input Status

Read Holding Registers

Read Input Registers

Force Single Coil

Force Single Register

Force Multiple Coil

Force Multiple Register

Read General References

Write General References

Response

512 Coils

512 Inputs

254 Registers

32 Registers

1 Coil

1 Register

800 Coils

60 Registers

NOT Supported

Table 21 184/384 PLC Maximum Parameters

Function

Code

Description

Read Coil Status

Read Input Status

Read Holding Registers

Read Input Registers

Force Single Coil

Force Single Register

Force Multiple Coil

Force Multiple Register

Read General References

Write General References

Response

800 Coils

800 Inputs

100 Registers

1 Coil

1 Register

800 Coils

100 Registers

NOT Supported

XXMIT 47

Table 22 M84 PLC Maximum Parameters

Function

Code

Description

Read Coil Status

Read Input Status

Read Holding Registers

Read Input Registers

Force Single Coil

Force Single Register

Force Multiple Coil

Force Multiple Register

Response

64 Coils

64 Inputs

32 Registers

4 Registers

1 Coil

1 Register

64 Coils

32 Registers

48 XXMIT

7.2

Cable Pinouts

You need to build an interface cable between your PLC and the modem or printer. The actual cable is connected to the Port which is supported by the

PLC and to the RS232 port of the modem or printer, or direct to another PLC’s

Modbus port. Because the XXMIT supports many modems and printers the pinouts are going to vary. Some pinouts are provided below.

9--pin (RS--232) to 25--pin (Modem) with no RTS/CTS Control

25--pin Male Adapter

9--pin Male

Pin 25

Pin 9

Pin 1

Front View

9--Pin

Connector

RXD 2

TXD 3

RTS 7

CTS 8

DSR 4

DTR 6

GND 5

Front View

Connector Pinouts

25--Pin D--shell

3 RXD

2 TXD

4 RTS

5 CTS

6 DSR

20 DTR

7 GND

XXMIT 49

Width: 185 mm

Height: 230 mm

50 XXMIT

9--pin (RS--232) to 25--pin (Modem) with RTS/CTS Control

25--pin Male Adapter

9--pin Male

Pin 25

Pin 9

Pin 1

Front View

9--Pin

Connector

RXD 2

TXD 3

RTS 7

CTS 8

DSR 4

DTR 6

GND 5

Front View

Connector Pinouts

25--Pin D--shell

RXD

TXD

RTS

CTS

6 DSR

20 DTR

7 GND

Width: 185 mm

Height: 230 mm

9--pin to 9--pin (Null Modem)

9--pin Male Adapter

Pin 9

Pin 1

Front View

9--Pin

Connector

RXD 2

TXD 3

RTS 7

CTS 8

DSR 4

DTR 6

GND 5

Connector Pinouts

9--Pin

Connector

3 TXD

2 RXD

7 RTS

8 CTS

4 DSR

6 DTR

5 GND

XXMIT 51

52 XXMIT

9--pin to 9--pin (Modem)

9--pin Male Adapter

Pin 9

Pin 1

Front View

9--Pin

Connector

TXD 2

RXD 3

RTS 7

CTS 8

DSR 4

DTR 6

GND 5

Connector Pinouts

9--Pin

Connector

TXD

RXD

RTS

CTS

DSR

DTR

GND

Width: 185 mm

Height: 230 mm

9--pin to 25--pin (Null Modem)

25--pin Male Adapter

9--pin Male Adapter

Pin 9

Pin 25

Pin 1

Front View

9--Pin

Connector

RXD 2

TXD 3

RTS 7

CTS 8

DSR 4

DTR 6

GND 5

Front View

Connector Pinouts

25--Pin D--shell

2 TXD

3 RXD

4 RTS

5 CTS

6 DSR

20 DTR

7 GND

XXMIT 53

54 XXMIT

RJ45--(8x8) to 25--pin (Null Modem) 110XCA20401

25--pin Male Adapter

Pin 25

Pin 1

RJ45 connector

(8x8)

Pin 1

RJ45

Connector

RXD 4

TXD 3

RTS 6

CTS 7

GND 5

DSR 2

Chassis

Ground

Front View

Connector Pinouts

25--Pin D--shell

TXD

RXD

RTS

CTS

GND

DSR

20 DTR

Chassis

Ground

Caution: Pin1 of the RJ45 receives 5V from the PLC.

Width: 185 mm

Height: 230 mm

RJ45--(8x8) to 9--pin (Null Modem)110XCA20301

Pin 1

RJ45

Connector

RXD 4

TXD 3

RTS 6

CTS 7

GND 5

DSR 2

Chassis

Ground

9--pin Male Adapter

RJ45 connector

(8x8)

Pin 1

Pin 9

Front View

Connector Pinouts

9--Pin D--shell

3 TXD

2 RXD

7 RTS

8 CTS

5 GND

4 DTR

6 DSR

Case of the

Connector

Caution: Pin1 of the RJ45 receives 5V from the PLC.

XXMIT 55

56 XXMIT

RJ45--(8x8) to 25--pin (Modem)110XCA20401

25--pin Male Adapter

Pin 25

Pin 1

RJ45 connector

(8x8)

Pin 1

RJ45

Connector

RXD 4

TXD 3

RTS 6

CTS 7

GND 5

DSR 2

Chassis

Ground

Front View

Connector Pinouts

25--Pin D--shell

RXD

TXD

RTS

CTS

GND

DSR

20 DTR

Chassis

Ground

Caution: Pin1 of the RJ45 receives 5V from the PLC.

RJ45--(8x8) to 25--pin (Modem)110XCA20401

25--pin Male Adapter

Pin 25

Pin 1

RJ45 connector

(8x8)

Pin 1

RJ45

Connector

RXD 4

TXD 3

RTS 6

CTS 7

GND 5

Chassis

Ground

Front View

Connector Pinouts

25--Pin D--shell

3 RXD

2 TXD

4 RTS

5 CTS

7 GND

6 DSR

20 DTR

Chassis

Ground

Caution: Pin1 of the RJ45 receives 5V from the PLC.

XXMIT 57

Width: 185 mm

Height: 230 mm

58 XXMIT

RJ45--(8x8) to RJ45--(8x8) (Modem)

RJ45 connector

(8x8)

Pin 1

RJ45

Connector

RXD 4

TXD 3

RTS 6

CTS 7

GND 5

DSR 2

Chassis

Ground

Connector Pinouts

RJ45

Connector

4 RXD

TXD

RTS

CTS

GND

DSR

Chassis

Ground

Caution: Pin1 of the RJ45 receives 5V from the PLC.

Width: 185 mm

Height: 230 mm

9--pin to RJ45--(8x8) (Modem)110XCA20301

Pin 1

RJ45

Connector

RXD 4

TXD 3

RTS 6

CTS 7

GND 5

DSR 2

Chassis

Ground

9--pin Male Adapter

RJ45 connector

(8x8)

Pin 1

Pin 9

Front View

Connector Pinouts

9--Pin

Connector

2 RXD

3 TXD

7 RTS

8 CTS

5 GND

6 DSR

4 DTR

Case of the

Connector

Caution: Pin1 of the RJ45 receives 5V from the PLC.

XXMIT 59

60 XXMIT

9--pin to RJ45--(8x8) (Modem)110XCA20301

Pin 1

RJ45

Connector

RXD 4

TXD 3

RTS 6

CTS 7

GND 5

Chassis

Ground

9--pin Male Adapter

RJ45 connector

(8x8)

Pin 1

Pin 9

Front View

Connector Pinouts

9--Pin

Connector

2 RXD

TXD

RTS

CTS

GND

DSR

DTR

Case of the

Connector

Caution: Pin1 of the RJ45 receives 5V from the PLC.

Width: 185 mm

Height: 230 mm

7.3

Cable Adapter Kits

You may want to purchase Cable Adapter Kits for your RJ45 (8x8) requirements rather than make them. The table below provides a list of available kits.

Table 23 Cable Adapter Kits

Description

RJ45--(8x8) to 25--Pin (Male)

RJ45--(8x8) to 9--Pin (Male)

RJ45--(8x8) to 9--Pin (Female)

RJ45--(8x8) to 25--Pin (Female)

Part Number

110XCA20401

110XCA20301

110XCA20302

110XCA20402

7.4

XXMIT Configuration using Hayes Compatible Dial--Up Modems (Only)

There are three commands that you need to become familiar with when interfacing dial--up modems to XXMIT. These commands are: Initialize modem,

Dial modem, and Hangup modem. Before an ASCII message or a Modbus message goes through the modem, you must first send an initialization string and then a dial string to the modem. Once the modem has dialed the telephone number and made a connection to the remote modem, you may send an unlimited number of ASCII messages or Modbus messages through the modem. To send multiple messages, you increment the message pointer to the next message after each successful XXMIT operation. When all messages are sent, you may then send the hangup string to the modem.

Initialization Message

The initialization message is just like any other ASCII message and may be a maximum of 512 characters long, although 50 characters is usually more than enough to initialize a modem. You may implement any Hayes AT command as part of the initialization string. We recommend the following commands when initializing a modem for use with XXMIT.

XXMIT 61

Table 24 Initialization Message for Dial--Up Modem

62 XXMIT

Note: While some modem manufacturers state full compatibility with

Hayes, they may still be slightly different. Therefore, we recommend using only those commands that have the same definition as those stated above.

The initialization message must always start with Hayes standard AT command.

The XXMIT block automatically precedes modem command messages with AT and appends the message with carriage return (0x0D) and line feed (0x0A) characters since these are required by all modem control messages. Other

(non controlling) ASCII messages do not have to end with a carriage return and line feed.

For example, a typical initialization message that XXMIT sends to the modem.

Message = (AT)&F&K0&Q0&D0V1X0Q0 (<CR><LF>) *

Length = 17 characters

For example, the initialization message may also be used to set S--registers of the modem.

Message = (AT)S0=1 (<CR><LF>) *

Length = 4 characters

*Characters within parentheses are automatically sent.

To have XXMIT send an initialization message to the modem, bit 7 and bit 16 of the command word must be ON. When bit 16 is ON, bits 15 and 14 must not be

ON or XXMIT will not complete the operation successfully. To actually send the message, Start input of XXMIT must come ON and stays ON until the operation is complete or an error occurs. When XXMIT determines the message was successfully sent to the modem, it turns ON the Done output. When an error occurs, the Error output comes ON. The Active output is ON while the message is being sent to the modem.

Expert: To eliminate some user logic programming, you may initialize the modem with parameters via a terminal program and not use XXMIT. Once the parameters are in the modem memory they may be saved to non---memory with an AT command, usually &W.

Dial Message

The dial message is used to send a telephone number to the modem. Only AT commands related to dialing a number should be included with the message.

Examples of typical dial messages used with XXMIT are shown below.

For example, dial telephone number using tone dialing.

Message = (AT)DT)6800326 (<CR><LF>) *

Length = 7 characters

For example, dial telephone number using pulse dialing.

Message = (AT)DP)6800326 (<CR><LF>) *

Length = 7 characters

For example, dial telephone number using tone dialing, wait to hear dial tone before dialing number, and pause before dialing the rest of the number.

Message = (AT)DT)W,6800326 (<CR><LF>) *

Length = 9 characters

*Characters within parentheses are automatically sent.

To have XXMIT send a tone dial message to the modem, bit 7 and bit 15 of the command word must be ON. When bit 15 is ON, bits 16 and 14 must not be

ON or XXMIT will not complete the operation successfully. To actually send the message, the Start input of XXMIT must come ON and stays ON until the operation is complete or an error occurs. When XXMIT determines the

XXMIT 63

Width: 185 mm

Height: 230 mm

64 XXMIT

message was successfully sent to the modem, it turns ON the Done output.

When an error occurs, the Error output comes ON. The Active output is ON while the message is being sent to the modem.

Expert: Because it takes so long for a local modem to make a connection to a remote modem, the timeout value, in RespTout should be quite long when sending a dial message to a modem. For example, set the timeout for

30,000 mS when sending a dial message. When the timeout value is too short, XXMIT issues a message timeout. You may have to try several settings before finding the optimal time.

Hangup Message

The hangup message is used to hangup the modem. Only AT commands related to hanging up the modem should be used in this message. An example of a typical hangup message is shown below.

For example, hangup modem message.

Message = (+++AT)H0 (<CR><LF>) *

Length = 2 characters

*Characters within parentheses are automatically sent.

When the hangup message is sent to a modem that is already connected to a remote modem, XXMIT must first set the local modem in command mode.

XXMIT does this by sending a escape sequence +++ to the modem. XXMIT assumes that +++ sets the modem in command mode. Some modem manufactures let the owner change this default escape sequence. For XXMIT to function properly the modem should be set to accept the +++ escape sequence.

To have XXMIT send a hangup message to the modem, bit 7 and bit 14 of the command word must be ON. When bit 14 is ON, bits 16 and 15 must not be

When an error occurs, the Error output comes ON. The Done output is ON while the message is being sent to the modem.

Expert: Because it takes so long for a local modem to hangup once it receives the hangup command, the timeout value, in RespTout should quite long when sending a dial message to a modem. For example, set the timeout for 30,000 mS when sending a dial message. When the timeout value is too short, XXMIT issues a message timeout. You may have to try several settings before finding the optimal time.

Width: 185 mm

Height: 230 mm

XXMIT 65