The IOLAN’s Digital I/O extension feature, sometimes referred to as I/O tunneling, provides a cable replacement solution by transmitting digital input signals to a remote output peer over an IP/ Ethernet network from PLC controllers, DCS systems or OEM equipment. Applicable to all IOLAN Ethernet I/O Device Server digital models, this feature can be used in various modes of operation.
Pass the state of a digital I/O input on one end and mirror this condition on the digital output on the other end. For example, a dry contact closure at one remote location can, in effect, be duplicated via a closure of a relay contact at another location using an IP Ethernet network.
RS232 control signals such as DSR, DCD and CTS can also be used as digital extension inputs to the IOLAN I/O Device Server. This is ideal where a contact closure is required at a remote location, but the source end point has an RS232 serial port instead of a pure digital I/O output. With a connection to its DB9 serial port, the IOLAN will pass the state condition to its remote peer accordingly.
IOLAN Ethernet I/O Device Servers can also be configured for multipoint operation where a single digital input condition can be duplicated or mirrored across up to 49 IOLAN digital outputs. This is ideal for redundancy applications where critical remote digital conditions need to be visible to multiple pieces of monitoring equipment simultaneously.
When a backup digital output location is required, the IOLAN Ethernet I/O Device Server automatic backup feature can be used. Whenever the primary session fails, the IOLAN will automatically seek to establish a session with a secondary IOLAN device. Once the primary session resumes, the source IOLAN will terminate the secondary session and resume sending events on the primary.
This exclusive feature, available only on secure IOLAN SDS I/O Device Servers, enables encrypted SSL sessions to be established for passing along digital state changes across an unsecured network. This prevents sensitive I/O state conditions from being monitored by unauthorized users or hackers.
Ethernet I/O Event Notification to a TCP/IP Application
Custom TCP/IP applications can be created to receive digital events from remote digital inputs such as alarms and contact closures. These applications can then record, notify and react to the digital event notification accordingly.
The Digital I/O extension feature’s event driven notification message is a simple 20 byte format enabling programmers to quickly develop an interface to remote IOLAN Ethernet I/O Device Servers.