Lee-Dickens - Next-generation remote control SCADA / telemetry units
Intelligent microprocessor based devices, for monitoring and controlling equipment at remote sites, have been introduced by Lee-Dickens. The Sitewatch MIDI 8 Remote Terminal Unit (RTU) represents the next-generation of class-leading RTU’s used primarily as part of a supervisory control and data acquisition system (SCADA) or a telemetry system, says the company.
The MIDI 8 uses the same distinctive IP65 rated moulded enclosure as the previous model, but the use of the latest compact surface-mount technology and RoSH components has freed up space for a number of additional features. These features include a broad range of interchangeable networking communication options including PSTN (fixed line modem), GSM and LAN Ethernet communications. The unit also has a transient to transmitter logic (TTL) interface that enables off the shelf modems to be used. This means a GSM or Ethernet modem can be easily swapped should it fail or the communications method need to be changed. The modems and radio transceivers are powered from the RTU itself and supported by standby batteries should mains power fail.
As well as increased networking options, additional I/O has been added. The Sitewatch MIDI 8 has 8 optically isolated digital inputs, 8 differentially selected analogue inputs and a further 3 digital outputs fitted as standard. The digital input capacity can be increased to 16 or 4 pulse inputs can be added by fitting a small expansion board. Digital and analogue inputs are configured by on-board links to provide a two wire interconnection to site equipment. A 24VDC 250mA supply is available to power external analogue transducers.
Each Sitewatch MIDI 8 has two serial data ports, one of which is configured for the Master Station communications interface and a second that can be used for local interrogation, connection to other RTU’s via a Local Area Network or for interfacing to other intelligent site equipment.
Source and more information: electropages