Product category:
HMIs/Operator Interfaces
News Release from: Status Instruments | Subject: HMI panels
Edited by the Engineeringtalk Editorial
Team on 17 February 2003
HMIs provide easy budget process control
Status Instruments has a cost effective range of human/machine interface panels, compatible with its highly successful "futureproof" MEDACS signal conditioning modules.
Status Instruments has a cost effective range of human/machine interface (HMI) panels, compatible with its highly successful "futureproof" MEDACS signal conditioning modules The MEDACS (modular expandable data acquisition and control systems) series represents a totally new and revolutionary concept in DIN rail signal conditioning modules, offering a high degree of functionality and configurability, together with the capability of interfacing to a wide range of industrial sensors
The HMI panels have a backlit LCD display and are sealed to IP65, making them suitable for use in harsh environments.
A variety of configurations are available, ranging from a relatively simple 2 x 20 character display with 128Kbyte of Flash memory up to one with 8 x 40 characters and 512Kbyte Flash memory.
Versions offering different user key and LED status indicator combinations can be selected to suit specific applications.
The HMI acts as a local Modbus master, collecting data from, and sending data to, a network of MEDACS slave devices to produce a local system with operator input.
In order to increase the flexibility of the MEDACS modules, Status has pioneered the development of its TFML transfer function module library, which is embedded in each MEDACS unit.
As Brian Turner, MD of Status, explains: "A conventional signal conditioner connects to a sensor and measures the sensor parameter, converting this to an industry standard output such as 4-20mA.
TFML offers the capability of inserting a transfer function between the input and output to provide a special control function.
This gives customers the ability to configure the units to accommodate unusual or custom applications directly within the signal conditioning module".
Each HMI unit has a number of dedicated keys which can be allocated to a particular function.
The operation is defined within the HMI using the Configuration Manager software supplied and the program stored in Flash memory.
Versions are also available with an in-built Basic scripting language to offer a greater degree of flexibility in development of the HMI application.
This, together with the versatility of TFML, enables multiple MEDACS units to be used together to create a powerful process control system.
Systems can be built up which take data from a wide range of sensors within a process, with individual MEDACS units processing specific groups of parameters, all co-ordinated within the HMI environment.
This can provide a highly cost effective and easier to program alternative to PLCs in many applications.
The lower cost versions have a single RS232/RS485 port which is used to program the HMI and then uses the same port to communicate with the MEDACS units, thus enabling the development of a stand-alone system.
More sophisticated versions have two ports which can be used to create a system that can communicate with a remote station as well as the MEDACS devices making it suitable for distributed control applications.
In this instance, the HMI can act both as a local Modbus master to the MEDACS slaves and as a remote Modbus slave to Scada/DCS systems. Request a free brochure from Status Instruments ...
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