Output Words

Output Words 4x ... 4x + 15

16 words of output data are used for 3 120VAC output points and commands for the Modbus master device.

The following table shows the function of the output words.

Output Words
Word 1	Sequence #
Word 2	Output configuration	AC output
Word 3	Control mode
Word 4	Port configuration	Slave Node
Word 5 ... 16	Message data field

Depending on how the application is written, moving a block of data to the registers, which includes a change in the sequence number, is acceptable.

Output Word 1

CAUTION

INVALID DATA - OUTPUT SHUT DOWN

Do not use a zero value in word one, which will cause an output shut down state.

Failure to follow these instructions can result in injury or equipment damage.

Valid settings are 1 ... FFFF.
The module defaults to zero at power-up (module shut down).
Whenever the module is set to zero, it goes to the module shut down state.
When the value in the first output word is not equal to the first input word, then a Modbus message will be sent.. When they are equal, there will be no message activity.
A change in the sequence word value starts the Modbus command execution. It is your responsibility to change the output data for the Modbus message. The sequence number must be the last word of information written in order to ensure Modbus messages are correctly handled.

Module Shut Down Definition

The Module shut down behaviour may be set to:

hold last value

- or -
user defined

- or -
minimum output (OFF)

NOTE: When the sequence number is 1 ... FFFF, the 120 VAC output and input data are collected every scan and are not affected by the sequence number. A sequence number of zero causes shutdown status, but inputs continue to be updated.

Output Word 2

Output word 2 contains 3 bits of 120 VAC discrete output data, 3 bits of user defined output data shut down values, and 2 bits for user shut down state.

Word 2 High Byte (Shut down states)
Bit 15	0= Shut down state minimum output 1= Check bit 14 for shut down state
Bit 14	0= Hold last value (shut down state) 1= User defined (shut down state)
Bit 13 ... 11	Not used
Bit 10	User defined value for output 3 (shut down)
Bit 9	User defined value for output 2 (shut down)
Bit 8	User defined value for output 1 (shut down)

Word 2 Low Byte (120 VAC output data)
Bit 7 ... 3	Not used
Bit 2	Output 3
Bit 1	Output 2
Bit 0	Output 1

Output Word 3

Output word 3 contains the Modbus message control mode.

Word 3 Control Modes
Mode	Value	Function	Description
Mode 0	0	Idle	No Modbus activity. Input buffer to zero
Mode 1	1	Modbus message	The I/O module executes the data field from a user-defined Modbus message
Mode 2	2	Block write	The I/O module performs a block write command (Modbus function code 16)
Mode 3	3	Block write and Block read	The I/O module performs mode 2 plus a block read command
Mode 4	4	4 single writes	The I/O module performs 4 Modbus function code 06 commands (single writes)
Mode 5	5	3 single writes and 1 block read	The I/O module performs 3 Modbus function code 06 commands (single writes) and Modbus function code 03 (1 block read command)
Mode 6	6	2 single writes and 2 block reads	The I/O module performs 2 Modbus function code 06 commands (single writes) and Modbus function code 03 (2 block read commands)
Mode 7	7	1 single writes and 3 block reads	The I/O module performs 1 Modbus function code 06 commands (single writes) and Modbus function code 03 (3 block read commands)
Mode 8	8	4 block reads	The I/O module performs Modbus function code 03 (4 block read commands)
Others	-	Illegal command	Response = illegal control mode

Output Word 4

Output word 4 contains the port configuration parameters (high byte) and the Modbus slave address (low byte).

Word 4 - Port Configuration
High Byte
Bit 15	0= 1 stop bit 1= 2 stop bits
Bit 14	0= 7 data bits 1= 8 data bits
Bit 13	0= no parity 1= parity enabled
Bit 12	0= odd parity 1= even parity
Bits 11 ... 8	0010= 19.2 baud others= 9600 baud
Low Byte
Bits 7 ... 1	Modbus slave node address