DeviceNet Modules, Series 90-30, Manual, GFK-2196

3Configuring a Strobed I/O Messaging ConnectionIn Strobed I/O mode, the master produces a single Strobe request message that is consumed by alldevices with a connection configured for strobing, requesting their current status. This occurs at therate selected using the Scan Interval parameter of the DeviceNet Master Module.Each strobed device then responds with its input data. Devices respond in the order of their MACIDs, beginning with the lowest MAC ID first. MAC IDs can be specifically assigned to prioritizeI/O reporting by the slaves.DeviceNetMasterStrobeMessageResponseSlave 1DeviceNet networkResponseSlave 2•••ResponseSlave nStrobed I/O Messaging can be more efficient than Polled I/O messaging because the master doesnot send an individual Poll request to each device. Strobed I/O Messaging is particularly useful forslave devices that have input data only, such as sensors.To configure Strobed I/O Messaging for a slave connection, select Strobed on the Slave Propertiesmenu.Strobed I/O Messaging Screen for a Series 90-30 DeviceNet MasterModuleFor input resources, specify the number of data bytes the device will send to the master.The length for output resources is automatically set to 1 byte. The message from the Master to theSlave telling them to send back their inputs is a 1 byte message. It reflects the state of the I/O bit inthe strobe request message for the device: set (1) or clear (0).3-18 Series 90®-30 Programmable Controller DeviceNet Modules – November 2002 GFK-2196