Communication Control Table

Memory Word	Name	Description	No Valid Entries
%MWx	Revision Number	Displays the current revision number of L9_XMIT function block. This number is automatically loaded by the function block and the function block over writes any other number entered into this word.	Read Only
%MWx + 1	Event Status	This field displays an event code generated by the L9_XMIT in port status mode. (For expanded and detailed information please see the Event Status Table).	Read Only
%MWx + 2	Available to User	The L9_XMIT function block does not use this word. However, it may be used in ladder logic as a pointer. An efficient way to use the L9_XMIT function block is to place a pointer value of a L9_TBLK function block into this word.	Read/Write
%MWx + 3	Data Rate	L9_XMIT supports the following data rates: 50, 75, 110, 134, 150, 300, 600, 1200, 1800, 2000, 2400, 3600, 4800, 7200, 9600 and 19 200. When used with Momentum, the choice is limited to 300, 600, 1200, 2400, 4800, 9600 and 19 200. To configure a data rate, enter its decimal number into this field. When an invalid data rate is entered, the function block displays an illegal configuration event (event code 127) in the Event Status (%MWx + 1) word.	Read/Write
%MWx + 4	Data Bits	L9_XMIT function block supports the following data bits: 7 and 8. To configure a data bit size, enter its decimal number into this word. Note: 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 function block displays an illegal configuration event (event code 127) in the Event Status (%MWx + 1) word.	Read/Write
%MWx + 5	Parity Bits	L9_XMIT function block 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 function block displays an illegal configuration event (event code 127) in the Event Status (%MWx + 1) word.	Read/Write
%MWx + 6	Stop Bits	L9_XMIT function block 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 function block displays an illegal configuration event (event code 127) in the Event Status (%MWx + 1) word.	Read/Write
%MWx + 7	Available to User	The L9_XMIT function block does not use this word. However, it may be used in ladder logic as a pointer. An efficient way to use the L9_XMIT function block is to place a pointer value of a L9_TBLK function block into this word.	Read/Write
%MWx + 8	Command Word	(16-digit binary number) The L9_XMIT interprets each bit of the command word as a function to perform. In Control Expert-IEC bit order: If bit 8 and 9 are on simultaneously or if any two or more of bits 0, 1, 2 or 3 are on simultaneously or if bit 9 is not on when bits 0, 1, 2, or 3 are on event 129 will be generated. For expanded and detailed information please see the Command Word Communication Functions Table.	Read/Write
%MWx + 9	Message Pointer Word	(message pointer) Values are limited by the range of %MW memory words configured. The message table consists of either ASCII characters For ASCII character strings, the pointer is the word offset to the first word of the ASCII character string. Each word holds up to two ASCII characters. Each ASCII string may be up to 1024 characters in length. For example, when you want to send 10 ASCII messages out of the PLC, you must program 10 ASCII characters strings into %MWx memory words of the PLC and then through ladder logic set the pointer to the start of each message after each successful operation of L9_XMIT. Modbus Function Codes For expanded and detailed information please see the section L9_XMIT Modbus Functions Enter a pointer that points to the beginning of the message table.	Read/Write
%MWx + 10	Message Length	(0 - 512) Enter the length of the current message. When the L9_XMIT function block is sending Modbus messages for function codes 01, 02, 03, 04, 05, 06, 08, 15 and 16, the length of the message is automatically set to five. When the L9_XMIT function block is receiving Terminated ASCII input the length of the message must be set to five or an event results. When the L9_XMIT function block is sending Modbus messages for function codes twenty and twenty- -one, the length of the message is automatically set to six. When the L9_XMIT function block is sending ASCII messages, the length may be 1 through 1024 ASCII characters per message.	Read/Write
%MWx + 11	Response Timeout (ms)	(0 - 65535 milliseconds) Enter the time value in milliseconds (ms) to determine how long the L9_XMIT function block 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, the L9_XMIT function block issues an event. The valid range is 0 through 65535 ms. The timeout is initiated after the last character in the message is sent.	Read/Write
%MWx + 12	Retry Limit	(0 - 65535 milliseconds) Enter the quantity of retries to determine how many times the L9_XMIT function block 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, the L9_XMIT function block issues an event and an event code. The valid range is 0 ... 65535 # of retries. This field is used in conjunction with response time-out (%MWx + 11).	Read/Write
%MWx + 13	Start of Transmission Delay (ms)	(0 - 65535 milliseconds) Enter the time value in milliseconds (ms) when RTS/CTS control is enabled, to determine how long L9_XMIT waits after CTS is received before it transmits a message out of the PLC port #1. Also, you may use this word even when RTS/CTS is NOT in control. In this situation, the entered time value determines how long L9_XMIT waits before it sends a message out of the PLC port #1. You may use this as a pre-message delay timer. The valid range is 0 through 65535 ms.	Read/Write
%MWx + 14	End of Transmission Delay (ms)	(0 - 65535 milliseconds) To determine how long the L9_XMIT function block keeps an RTS assertion once the message is sent out of the PLC port #1, enter the time value in milliseconds (ms) when RTS/CTS control is enabled, After the time expires, the L9_XMIT function block ends the RTS assertion. Also, you may use this word even when RTS/CTS is NOT in control. In this situation, the entered time value determines how long the L9_XMIT function block waits after it sends a message out of the PLC port #1. You may use this as a post-message delay timer. The valid range is 0 through 65535 ms.	Read/Write
%MWx + 15	Current Retry	The value displayed here indicates the current number of retry attempts made by the L9_XMIT function block	Read Only

Memory Word

Name

Description

No Valid Entries

%MWx

Revision Number

Displays the current revision number of L9_XMIT function block.

This number is automatically loaded by the function block and the function block over writes any other number entered into this word.

Read Only

%MWx + 1

Event Status

This field displays an event code generated by the L9_XMIT in port status mode.

(For expanded and detailed information please see the Event Status Table).

Read Only

%MWx + 2

Available to User

The L9_XMIT function block does not use this word. However, it may be used in ladder logic as a pointer. An efficient way to use the L9_XMIT function block is to place a pointer value of a L9_TBLK function block into this word.

Read/Write

%MWx + 3

Data Rate

L9_XMIT supports the following data rates: 50, 75, 110, 134, 150, 300, 600, 1200, 1800, 2000, 2400, 3600, 4800, 7200, 9600 and 19 200.

When used with Momentum, the choice is limited to 300, 600, 1200, 2400, 4800, 9600 and 19 200.

To configure a data rate, enter its decimal number into this field. When an invalid data rate is entered, the function block displays an illegal configuration event (event code 127) in the Event Status (%MWx + 1) word.

Read/Write

%MWx + 4

Data Bits

L9_XMIT function block supports the following data bits: 7 and 8.

To configure a data bit size, enter its decimal number into this word.

Note: 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 function block displays an illegal configuration event (event code 127) in the Event Status (%MWx + 1) word.

Read/Write

%MWx + 5

Parity Bits

L9_XMIT function block 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 function block displays an illegal configuration event (event code 127) in the Event Status (%MWx + 1) word.

Read/Write

%MWx + 6

Stop Bits

L9_XMIT function block 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 function block displays an illegal configuration event (event code 127) in the Event Status (%MWx + 1) word.

Read/Write

%MWx + 7

Available to User

The L9_XMIT function block does not use this word. However, it may be used in ladder logic as a pointer. An efficient way to use the L9_XMIT function block is to place a pointer value of a L9_TBLK function block into this word.

Read/Write

%MWx + 8

Command Word

(16-digit binary number)

The L9_XMIT interprets each bit of the command word as a function to perform.

In Control Expert-IEC bit order: If bit 8 and 9 are on simultaneously or if any two or more of bits 0, 1, 2 or 3 are on simultaneously or if bit 9 is not on when bits 0, 1, 2, or 3 are on event 129 will be generated.

For expanded and detailed information please see the Command Word Communication Functions Table.

Read/Write

%MWx + 9

Message Pointer Word

(message pointer)

Values are limited by the range of %MW memory words configured.

The message table consists of either

ASCII characters

For ASCII character strings, the pointer is the word offset to the first word of the ASCII character string. Each word holds up to two ASCII characters. Each ASCII string may be up to 1024 characters in length. For example, when you want to send 10 ASCII messages out of the PLC, you must program 10 ASCII characters strings into %MWx memory words of the PLC and then through ladder logic set the pointer to the start of each message after each successful operation of L9_XMIT.
Modbus Function Codes

For expanded and detailed information please see the section L9_XMIT Modbus Functions

Enter a pointer that points to the beginning of the message table.

Read/Write

%MWx + 10

Message Length

(0 - 512)

Enter the length of the current message. When the L9_XMIT function block is sending Modbus messages for function codes 01, 02, 03, 04, 05, 06, 08, 15 and 16, the length of the message is automatically set to five. When the L9_XMIT function block is receiving Terminated ASCII input the length of the message must be set to five or an event results. When the L9_XMIT function block is sending Modbus messages for function codes twenty and twenty- -one, the length of the message is automatically set to six. When the L9_XMIT function block is sending ASCII messages, the length may be 1 through 1024 ASCII characters per message.

Read/Write

%MWx + 11

Response Timeout (ms)

(0 - 65535 milliseconds)

Enter the time value in milliseconds (ms) to determine how long the L9_XMIT function block 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, the L9_XMIT function block issues an event. The valid range is 0 through 65535 ms. The timeout is initiated after the last character in the message is sent.

Read/Write

%MWx + 12

Retry Limit

(0 - 65535 milliseconds)

Enter the quantity of retries to determine how many times the L9_XMIT function block 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, the L9_XMIT function block issues an event and an event code. The valid range is 0 ... 65535 # of retries. This field is used in conjunction with response time-out (%MWx + 11).

Read/Write

%MWx + 13

Start of Transmission Delay (ms)

(0 - 65535 milliseconds)

Enter the time value in milliseconds (ms) when RTS/CTS control is enabled, to determine how long L9_XMIT waits after CTS is received before it transmits a message out of the PLC port #1. Also, you may use this word even when RTS/CTS is NOT in control. In this situation, the entered time value determines how long L9_XMIT waits before it sends a message out of the PLC port #1. You may use this as a pre-message delay timer. The valid range is 0 through 65535 ms.

Read/Write

%MWx + 14

End of Transmission Delay (ms)

(0 - 65535 milliseconds)

To determine how long the L9_XMIT function block keeps an RTS assertion once the message is sent out of the PLC port #1, enter the time value in milliseconds (ms) when RTS/CTS control is enabled, After the time expires, the L9_XMIT function block ends the RTS assertion. Also, you may use this word even when RTS/CTS is NOT in control. In this situation, the entered time value determines how long the L9_XMIT function block waits after it sends a message out of the PLC port #1. You may use this as a post-message delay timer. The valid range is 0 through 65535 ms.

Read/Write

%MWx + 15

Current Retry

The value displayed here indicates the current number of retry attempts made by the L9_XMIT function block

Read Only