Schneider Electric LUFP9 user manual Configuring the Response

6. Configuring the Gateway

6.11.2.3. Configuring the Response

Next select the “Response” element from the Modbus command. The various elements of the configuration of the response for this command are shown opposite. The values displayed correspond to the default values for any new command.

These elements allow you to configure a single aspect of managing the command, described at the top of the page on the right. Each of these elements is described, in order, in the table below.

Configuration	Description
element
Trigger byte	This element is used by the gateway to activate the unitary incrementation of an 8-bit
	counter in order to notify the DeviceNet master of the receipt of a new response to the
	associated Modbus command. It takes one of the following two values:
	- Disabled	Default configuration. The gateway does not increment any
	counter on receipt of the Modbus response.
	- Enabled	Each time that the gateway receives a new response to the
	associated Modbus command, it increments the value of an 8-bit counter designated
	by the “Trigger byte address” element (see below). If used, this counter allows the
	DeviceNet master, for example, to only consider the response’s corresponding data
	when this counter’s value is incremented.
Trigger byte	This element is only used by the gateway if the element “Trigger byte” is set to “Enabled”. In
address	this case, it specifies the address, in the gateway’s input memory (16#0002 to 16#0002), of
	an 8-bit counter managed by the gateway.
	When the gateway receives a response to the associated Modbus command, it increments
	the value of this counter in a unitary manner (value = value+1). So the DeviceNet master
	must have access to this counter in the same way as for the periodic input registers from
	the TeSys U motor starters.
	This mode allows the DeviceNet master to be informed that a new response is available.
	This can be useful, for example, if it is possible that the data from two consecutive
	responses may be identical.
	N.B.: In the specific case of the gateway’s default configuration, the “Trigger byte” element
	for responses to the “Transactions 1” and “Transactions 2” personalized commands of the
	“TeSys U n°1” node is set to “Enabled”. Hence, the management of responses to read and
	write commands for parameters is event driven.
	The “Trigger byte address” elements of the “Response” elements for these two commands
	are configured at addresses 16#001E and 16#001F. These are the “parameter read/write
	response counters”. Considered under DeviceNet and RSNetWorx, these two data are
	configured the same way as the other inputs (see chapter 4.2.6Configuring Inputs from the
	Gateway, page 29) and both correspond to the I:1.16 input.
	The DeviceNet master PLC will be able to detect the receipt of a response from a Modbus
	slave by comparing the previous value and the current value of the associated counter
	(address 16#001E or 16#001F). If there is a unitary incrementation of this counter, the PLC
	may, for example, read all of the data from the response (addresses 16#0013 to 16#0017
	or addresses 16#0018 to 16#001D) and allow the transmission of a new query for reading
	or writing the value of a parameter (using a “Trigger byte” for the queries). Contrarily to the
	counter one can associate to the queries of any command, a response’s “Trigger byte” is a
	true modulo 256 counter, i.e. zero must be managed (… 254, 255, 0, 1, 2 …).

E.g. With the ATS48, we do not want the response to be event driven. So we will be retaining the default configuration.

69