Just as one of my experiences with Yokogawa’s ProSafe-RS(R 2.02.00) system which may be useful for other control engineers to know.

Online configurability means, you can change logics and take them into effect by downloading the modified logics into the controller (while the controller is running the old logics) without affecting the normal operation of the controller and without forcing the controller to cold or warm restart.

When it comes to online configurability feature for ESD (or DCS) systems, most vendors claims their systems supports this capability as it was the case for me when holding meeting with Yokogawa (for their ProSafe-RS system) during the early stage of our ESD vendor selection.

Now after several years passed from that meeting and awarding Yokogawa, we are facing with problems with so called online configurability of ProSafe-RS system! Despite all technical reasons which surely are logical, ProSafe-RS system we have, cannot be configured online and we have to wait for next overhaul of the plant to be able to download some changes we have made in ESD software and this completely violates the online configurability feature we expected and asked from Yokogawa.

Referring to section 5.2 of Yokogawa’s instruction manual IM 32S01C10-21E 2nd Edition entitled “List of Applicable Items for On-line Change” we noticed that although they claimed their system is online configurable but ProSafe-RS is actually “conditional online configurable” which is very far from the concept we were looking for at the bidding stage.

I confirm that ProSafe-RS system is one of the best systems to be used for ESD but I believe they have to still improve its capabilities.

 

Dear Friend,

Try to understand the boundaries between a DCS & SIS(ESD). As far as ESD(SIS) concerned the Safety standards restrict/ limit the number and type of ON-LINE Modifications and that's the reason why even if you go with a TMR SYSTEM LIKE TRICONEX many crucial on-line changes will be limited or inhibited since purpose is functional safety and hence reliability and functionality not to be compromised at all while plant running.

However the latest s/w and h/w version Prosafe-RS (R3.XXX) do supports many on line changes except few of the below.

1. development of a new type customized function blocks.

2. Addition of new nodes.

The most disadvantageous on Prosafe-RS i could see (since we have huge installation R3xx Version) is the Programming s/w (ISAGRAPH) which has many bugs, also the size of the system is small and type of I/Os are very limited or less number of channels hence you need to go for many NODES.

I believe being a pioneer in Process Automation as like Honeywell they must come out with a SIS with larger in size incl. I/Os as well as more reliable Programming s/w options LAD,IL,STL and CE environment.