Overview
Where alarm systems in a highly volatile environment, such as a petrochemical plant, are concerned, simplicity has to be one of the keywords. Not every person on-site, nor even every member of staff, will be a trained engineer capable of dealing with a potential emergency. Mistakes can be made, and, if there are no fail-safe structures in place, problems can escalate.
This is why Valero turned to IES when they needed to upgrade the alarm systems in their control rooms. Valero’s engineers needed to work with other engineers, people who were capable of grasping the essentials, and who would be able to work effectively and efficiently as they upgraded the existing system and ensured that the new structure was sufficiently flexible to operate in a wide range of control rooms for many years to come.
The Task
- To upgrade and modernise the existing hardwired alarm mimics systems in control rooms
- To design, develop, test and implement a modern digital solution
- To ensure that the new system was ‘future-proof’ and portable throughout a range of control rooms
The Challenge
The requirement was for a large and complex system. A Human Machine Interface (HMI) needed to be designed and installed, supporting up to 128 alarms, and to be configured in thirty different alarm groups, each group having a capability of triggering sixteen alarms.
The system needed to be capable of assigning 128 alarms to 360 alarm cells via the HMI. In addition, there was a requirement for an automatic check to be designed in order to overcome user error the during the alarm assignment to the various groups.
The Strategy
IES designed a control panel that housed the Programmable Logic Controller, all the hard-wired alarm signals and the interfaces with the Distributed Control System. The existing hard-wired Mimic was replaced with the new control desk-mounted HMI panel. The necessary software for the Programmable Logic Controller and the HMI panel was designed and developed in accordance with the client’s specifications and requirements.
The Design and Implementation Teams
Hardware and software designers and engineers collaborated at all stages of the upgrade and the development to ensure that the new system could be implemented as seamlessly as possible. The client’s requirement for the alarm structures to be fit for purpose for the foreseeable future, as well as being sufficiently flexible to operate in a range of control rooms, called for the best in qualified and experienced teams to handle a demanding challenge.
The Result
The Critical Alarm Mimic System that IES produced exceeded Valero’s expectations. It is universal, lean, well-designed and beautifully packaged. It is portable, reliable and flexible, and can easily be re-used or re-produced for implementation in other control rooms across Valero’s sites.
With the configuration of the Human Machine Interface Name, the Group Title, the Group Response Message, the Alarm Description, and the enabling and disabling of the individual alarms (including maintenance overrides and mapping alarms) to different groups, all of which can be configured through the HMI, this on-site system is not only user friendly, it is also simple to expand or to modify.
This challenging task was accomplished on time, and to the satisfaction of the client. Once again, the IES system of engineers talking to engineers has proved the value of a clear understanding of the requirements, coupled with a co-operative approach and an ability to balance a range of skills, qualifications and experience. Where engineering solutions are required, engineers look for other engineers. IES has those other engineers.
Did You Know?
Possibly the very earliest complex HMI (Human Machine Interface) was the Jacquard Loom. Invented by Joseph Jacquard and first demonstrated in 1801, this was an attachment for powered fabric looms which used a chain of punch cards to instruct the loom on how to make intricate textiles. The system was then used for early computers.
Xenophon the Greek soldier and historian writes about alarm systems: “The Persian army is then subject to great inconveniences, for their horses are tied and generally shackled to prevent them from running away, and if an alarm happens, a Persian has the housing to fix, his horse to bridle, and his corset to put on before he can mount.”
In a recent competition for work safety slogans, one of the losers was: “In case of fire, leave the building before putting it on Facebook.”