Schneider Electric LUFP9 user manual Configuring the Query, Configuration Description Element

6. Configuring the Gateway

6.11.2.2. Configuring the Query

Select the “Query” element from the Modbus command. The various elements of the configuration of the query for this command are shown opposite. The values displayed correspond to the default values for any new command.

These elements allow you to configure how the whole command is managed, including how degraded modes are managed (number of re-transmissions, for example).

Each of these elements is described, in order, in the table below. When a unit is assigned to an element, it is shown in brackets after the name of the element:

Configuration	Description
element
Minimum time	This element is only relevant if you have added a “Broadcaster” node (see chapter 6.13
between	Adding a Broadcaster Node, page 79). This parameter then allows you to specify a waiting
broadcasts	time following the transmission of the selected broadcast command. The next Modbus
(10ms)	message, whatever it is, will only be transmitted by the gateway once this time has elapsed.
	So it needs to be long enough to allow the slowest Modbus slave to process the command
	which has been broadcast. This parameter is not used by commands which do not belong
	to a broadcaster node.
	With the LUFP9 gateway’s default configuration, this feature has not been used, so as to
	control the Modbus slaves individually.
Offline options	This element affects the data sent to the Modbus slave, but only in the query to which this
for fieldbus	element belongs to, whenever the gateway is disconnected from the DeviceNet network. This
	element takes one of the following three values:
	- Clear ............. From now on all data sent to the Modbus slave using this query is set to
	16#0000 (resetting of the output data in the gateway’s memory).
	- Freeze........... All data sent to the Modbus slave using this query retains its current values
	(the output data in the gateway’s memory is frozen).
	- NoScanning .. The query is no more transmitted to the Modbus slave by the gateway.
Offline options	This element affects the data sent to the DeviceNet master PLC whenever the query to
for sub-network	which this element belongs to has not been answered with a response by the Modbus slave
	(no response). This element takes one of the following two values:
	- Clear ............. From now on the data sent to the DeviceNet master PLC is set to 16#0000
	(resetting of the input data in the gateway’s memory).
	- Freeze........... From now on the data sent to the DeviceNet master PLC retains its current
	values (the input data in the gateway’s memory is frozen).
	N.B. exception responses issued by the Modbus slaves do not trigger the use of these “Offline options!”
Reconnect time	If there is no response from the Modbus slave to a query, or following the receipt of an
(10ms)	incorrect response, the gateway uses the “Retries” and “Timeout time (10ms)” elements to
	carry out re-transmissions. If the Modbus slave has still not responded correctly following
	these re-transmissions, the gateway stop sending it the corresponding query for a period of
	time which can be adjusted using “Reconnect time (10ms)”.
	When this period is over, the gateway attempts to restore communication with the Modbus
	slave.

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