Microstar Laboratories has announced an signal interface (SI) module, part number MSXB 074, with current loop transmitters for eight control points.
The product complements an existing SI module, part number MSXB 086, a current loop receiver that can monitor 16 inputs.
SI module MSXB 074 derives each current output from a 16-bit DAC on each channel.
The module provides channel-to-channel isolation - important for process control - and uses loop power.
The actual range is 0-24mA, and this extended range lets you use the product to test any 4-20mA circuits: 0mA simulates an open circuit and 24mA is 20 per cent over the normal range.
Like other SI modules, MSXB 074 connects to a DAP board directly controlled by a PC or by a DAPserver.
The DAP can send dynamic signals to the current outputs on the MSXB 074 SI module at an aggregate update rate as high as 1M updates/s.
Each DAPserver - a complete data acquisition and control package - contains up to four DAPs, and each DAP communicates with, configures, and controls many SI modules connected to it.
A system consists of any number of networked DAPservers, and includes as many SI modules as the application requires.
However many sensors and actuators are in the system, and however spread out they are, the user is covered.
Users can also include voltage inputs and outputs as well as current loops in the same application.
For smaller systems, users may need only a single DAPserver.
This can be hooked up to any PC with an Ethernet connection.
Users can also work directly on the DAPserver by adding a screen, and connecting a keyboard and mouse to the front-panel USB ports.
The new MSXB 074 SI module joins a growing family of SI modules related to an established family of intelligent products.
All SI modules are intelligent: each includes a field-programmable gate array (FPGA) programmed to communicate with, be configured by, and respond to commands from a DAP.
Every DAP is intelligent: each includes an onboard processor running a real-time operating system that communicates with, is configured by, and responds to commands from a PC application.
For the application users can utilise DAPstudio - data acquisition development software from Microstar Laboratories - or a third-party product, like Labview.
Users can run the application on a DAPserver or on any PC on a network.
The DAP does not have to be local to the PC that controls it.
Users communicate with their application on a PC - and the software takes care of the details, right down to what happens on the SI module.
SI modules like MSXB 074 fit into a backplane in a standard industrial enclosure as do other products that conform to the hardware specifications of the Microstar Laboratories channel architecture: signal connectors on 3U (100mm high) Eurocard B (220mm deep) boards - Eurocards - that often pre-process a signal.
Signals connect to a DB37 connector or to Wago connectors.
A backplane connector on each board connects it to a digital backplane factory-fitted into the industrial enclosure.
An interface board that also plugs into the backplane transmits digitised waveforms to or from a DAP board controlled from a PC or DAPserver.
Each DAPserver includes a 10-slot Eurocard cage with a preinstalled backplane for SI modules like MSXB 074.
Separate industrial enclosures are required only when this 10-slot limit is exceeded.
If the application requires voltage inputs and outputs as well as 4-20mA current inputs and outputs, users can choose from a range of SI modules for analogue input, analogue output, analogue input and output, and digital input and output.
The SI designation is reserved for MSXB products that are intelligent: those that a DAP can communicate with and configure.
All new MSXB products are SI modules.
The full range of SI modules and earlier MSXB products is described on the company website.
SI modules all include the level of isolation required to prevent ground loops.
Using these boards saves users from having to take other steps against this common nuisance.
If spurious currents are corrupting signals, the application is not doing the job you want it to do.
If users need to monitor or control any number of sensors and actuators using 4-20 mA current loops and want the convenience of a network-ready Windows solution, the SI modules from Microstar Laboratories should be considered.
A system based on these modules is designed to scale up to however many current loops are needed.
Users can install the modules in an industrial enclosure and connect them to a DAP board they control from a PC, or they can install them directly into a rack-mountable DAPserver that contains one or more DAP boards.
Users control DAP boards by using DAPstudio - or other Windows software - on any PC or DAPserver on a network.
