Comparison of DCS


Thread Starter


Dear all,

I am working as instrumentation design engineer. Does anybody have the DCS comparison matrix with the following points? Please send it to my e-mail id: a_nana05 @ yahoo. co. in.

I need ABB 800A and Emerson DeltaV comparison, that is enough.

(1) System effectiveness
(2) Technical performance
(3) Capability
(4) Availability
(5) Support effectiveness
(6) Reliability
(7) Maintainability
(8) Safety
(9) Accessibility
(10) Software configuration
(11) Quality
(12) Software enhancement
That's a fairly large request for a forum thread!!!

To put it simply, and I have had experience with both systems, I would go for DeltaV every time.

Try spending a few minutes Googling each ABB 800 and DeltaV, this should provide most of the comparative data you require. Just beware, most of it will be Sales spiel!
And other people would choose the opposite, fribby.

What I recommend, when people ask me what the best DCS is, is to spend time in the pre-design phase getting all the vendors on the short list to give you customers to talk to, and really go interview them in depth...ask them how they do certain things, how difficult it is to do the things you want to do, and what they really think.

Clearly no vendor is going to give you an angry customer to talk to, but many will give you HONEST customers, who will tell you what the bear did in the woods, complete.

If you want the best DCS you can get, specify the functions in detail that you want, and get detailed proposals on how they'll handle each function. If they don't want to do that, there are other vendors.

If you don't know exactly what you want, you will get exactly what you are sold.


Walt Boyes
Editor in Chief Control and
Mailto:[email protected] Read my blog SoundOFF!! At

Chris Jennings

I would suggest that if you are going to compare two particular DCS systems you need to list all the specific requirements for your installation. e.g.

- Redundant controllers (do you need it, to what level)
- I/O (what configurations are required e.g. Fieldbus, Profibus)
- System size (how big is your system, I/O counts, PID loops)
- Engineering work flow, online configuration, change management (how do you work with the control system)
- HMI (update rates, integration with other systems using OPC, historian requirements)
- Integration with business systems (SAP, OSI PI, etc.)

If you have specific requirements for your DCS you can ask the vendors questions like "Which other sites have this DCS system version that are the same size as our installation?", "What problems did they encounter?" or "We need to communicate with our other control system XYZ, how can you implement this with your system?"

All too often people don't know what they want, and end up being railroaded by the sales people into thinking that they need all the other stuff that isn't actually ever going to be used. I still haven't worked on a DCS that has fully utilised all of its features and capabilities.

If you are only interested in the engineering side of things, it might be worth doing the basic system courses for both systems. These courses are good because you get a good overview and you get to play with the system. The courses are always a good chance to network with other users as well, they will be happy to tell you what they think is "wrong" or "good" with the system. On the course try to break it, configure it the wrong way and see what happens, pull controllers out on the run and experiment.

Every system has its good and bad points, having used both DeltaV and 800xA they both have strengths and weaknesses. What your job is, is to work out if you can match your NEEDS with the system STRENGTHS. Don't choose a system that almost does everything, but does the most important thing badly.

Chris Jennings


Another option is to appoint a consultant for the
project who is familiar with all the DCS.

We can provide you this service. We are basically
process control people & implement DCS projects
as indicated by WBOYES - editor.

We also stress on architecture for requirement.

[email protected]

A PLC Programmer

Dear Narayan,

The simple answer to your question lies in two facts:

a) How much locally a DCS vendor is present in your area.

b) If vendor is a Sales team or a Solution Provider team.

Two different vendors of same DCS Brand & Model in two different parts of this world may be opposite in service & solution provision.

Moreover a good Solution Provider Sales Engineer may cover all the ambiguities of his product.

Hope you got the point & will research your local DCS solution provider market.


A PLC Programmer
Almost all DCS providers can supply your requirements very well, but the real question is: can do it his local office?

This is the most important question that you must have. All DCS systems have the ability to develop your requirements but the secret is who is making the configuration of the DCS to cover your application and how is the future support can you get about the application implemented. Not all developers can implement in a easy way your aplication and therefore in the future, you can get some problems to implement additions and modifications

Look for a very good local technical support, and so you can sleep more time.

I am an instrumentation engineer,

I think in choosing the DCS one should atleast have two years of experience on each ABB, Honeywell, Yokoghawa, Siemens, Emerson, etc..
for me main important points are,

2.Engineering Ease.
3.Online Changes Possible.
4.Easy Third Party Interface.
5.Easy To Learn.
6.Good Service.
7.Better Historization.
8.Attractive And User Friendly Graphics.
9.Less Wires.
10.No Problems For Redundancy Sync.

Manish Deogade

Dear all,

I am working as instrumentation engineer. This matrix may help you. Give feedback Please send it to my e-mail id:
[email protected]

1 1:1 Controller redundancy available
2 Min scan time of I/Os
3 Min scan time of controller
4 Controller to controller transfer time atleast 50 variables /sec
5 Redundancy of network
6 Online Changeover/Hotswapping of Redundant controller/IO cards and other accessories.
7 Provision of barriers on I/O signals - Internal / External
8 20% spare wired capacity
9 20% space for future I/O
10 I/O card to FTA - Plug/socket cable
11 D/I - Electrically isolated from each other and system power supply
12 D/I - Volt free contact as input.
13 D/O - Volt free contact + supply looping
14 D/O - Rating 24V DC 1.0 A
15 A/I - electrically isolated from each other
16 A/I - Loop 600Ω
17 A/I - Accuracy - ± 0.2%
18 A/I - Support 2 wire / 4 wire
19 A/O - Loop 700Ω
20 A/O - Accuracy - ± 0.25%
21 Pulse input - 0 - 5khz, 4-24 V DC
22 Humidity allowable
23 Temp allowed
24 Environment protection class - G3
25 Availability time min99.99%
26 MTTR 8 hrs
27 MTBF 80000 hrs
28 failing of input to controller shall result in o/p going to fail safe condition
29 Processor cabinets
30 "Density of points on cards
31 Availability of speed/counter module
32 Switch offered
33 Control and Plant network separate
34 Hardware for connecting spinning OS
35 All diode oring shall be 3 inputs - 2 inputs connected, one as spare
36 All closed loop redundancy considered
37 Controller loading must not exceed 50 %
38 Separate panels for System, I/O and power
39 The front and rear access shall be considered subject to the panel layout.
40 Lifting lugs provision
41 Rittal type
42 EMC compliant
43 IP30 min protection
44 100mm plinth
45 Same key/lock for all panels
46 Bottom gland entry
47 Removable gland plate
48 Color RAL7035
49 40% spare capacity in trunking
50 Power / IS / Non IS wiring separated
51 IS Blue terminals
52 Knife edge rail mounted terminals
53 I/O cards protection available - fuse
54 20% spare terminals
55 Isolation switch for each cabinet
56 No of Marshalling cabinets
57 I/O requirement included
58 Quantity of commissioning spares
59 Inlet power supply system - 110V AC / Utility - 230 V AC
60 Power capability to include future I/O
61 Each power supply unit to loaded less than 50%
62 redundancy in power supply
63 Loading calculation to be provided
64 Power supply tolerance limits of the system during UPS failure,mains born noise,“burnout” and transient over voltage conditions without a UPS system
65 Capability to provide sequence control
66 Capability to provide ladder logic control
67 Capability to provide regulatory control
68 Capability to provide logic control
69 Complex calculation
70 System configuration
71 Project management
72 Simulation
73 Command switch over to final synchronisation time
74 Max time between power cycle and initial sync completion
75 Online Software upgrade possible
76 Online Firmware version upgrade possible
77 Control loop scan time 90% loops - 1 sec
78 Control loop scan time 10% loops - .25 sec
79 Indication loop - 1 to 10 sec
80 Digital - 1 sec
81 System availability
82 Redundancy of harddisk
83 Backup media
84 Backup provision
85 Server Class machine
86 Redundancy of Power supply
87 Alarm Management s/w available - Existing software to be used
88 Alarm priorities available
89 Alarm color distinguition
90 Alarm logging time < 1 sec
91 Operating mode - min 6 shall be available
92 System access - Password/ Key locking
93 capable of displying alarm, sequence message, diagnosis messages
94 HMIs + Printer included
95 Monitor type
96 History option
97 Operator keyboard - Special KB required with additional keys for ramping. Ack. Silence
98 Redundancy of harddisk
99 Backup media
100 Backup provision
101 Server Class machine
102 Redundancy of Power supply
103 OPC provision
104 Interface PC included in scope of supply
105 simultaneous connection to DCS and External LAN
106 Security provision - Firewall included
107 On line installation of DCS Node possible
108 Retriving plant parameters in excel sheet
109 Archive process data
110 Analyse stored data
111 Play back recorded data
112 Exchange data with external PC- excel sheet.
113 Alarm management system to be connected to plant LAN.
114 Connectivity to IP21 server
115 Connectivity to APC server
116 Registry for running consumed and spare IOs
117 Production reoprt generation daily/weekly and monthly.
118 Capability to provide serial communication
119 Ports available RS232/422/485
120 Protocol available - Modbus
121 Redundancy available
122 Communication cable and converter included in scope of supply
124 Time Synchronisation: Possible to connect external master clock
125 Available
126 Integral / external card
127 AMS software provided
128 AMS station provided
129 Display call up time - 4 sec (Time between display call up and display appearing with all dyn value updated)
130 Display dynamic update time - 4 sec (Time between change in value and display showing change value)
131 Alarm display - 1 sec ( Time between change in state and alarm appearing on display)
132 Hard copy - 1 min ( Requesting hard copy and getting printout)
133 Alarm discrimination time - 1 sec ( Min time between occurrence of two alarms necessary for the system to able to identify)
134 Simultaneous alarm handling - 5 sec ( Max time between the occurrence of 40 simultaneous alarms and their appearance on display
135 Communication loading < 50% under upset condition
136 Controller loading < 60%
137 Historian Loading < 60%
138 Loading calculation to be provided
139 Latest software
140 Support for software upgradation free
141 After sales upgradation of softwares release and support for 5 years
142 max displays 250
143 Group display - 6-10 loops
144 capable of logging alarm, sequence message, diagnosis messages, event, operator actions
145 Reports at least 10
146 Trend - capable of trending input, output and setpoint
147 30 days storage time at 1 min interval
148 Real time trend min 30 mins < 5 sec interval
149 Scaling of axes
150 historical data downloading to excel
151 Software licenses
152 Anti-virus updation will be on VENDOR scope.
153 2 years spares included in quotation
154 Spares requirement and cost for next 3 years
155 Commissioning spares
156 Local spare support
157 Spares support after obsolesce
158 Quality control
159 Country of build
160 Country of engineering
161 Country of FAT
162 FAT included with 3rd party serial links testing
163 Installation in vendor's scope
164 Interpanel wiring - In vendor's scope
165 Earthing cables included in scope of supply
166 Power cable included in scope of supply
167 Shutdown time quoted for change over
168 No of days included in scope to provide engineers
169 Domain based system
170 Domain server separate
171 Type of Network
172 Constraints for online change over
173 Operator training included/ No of persons
174 Maintenance training included/ No of persons
175 Engineering training inlcluded / No of persons
176 Country of Origin
177 Delivery Period
178 Compliance with ISA Standards
179 Warranty
180 AMC after Sales
181 Response to customer queries
182 Support and lead time to reach at site
183 Documentation
You can make an almost endless list of different kinds of hardwired input and output types a DCS should support, but it is 2011 and if you buy a new DCS you really should be using bus as far as possible so the DCS should support FOUNDATION fieldbus for control, PROFIBUS-DP for motor controls, the integrated SIS shall support HART, plus you want WirelessHART support so you can add wireless devices later in the project or during operation. These protocols integrate with intelligent device management software thanks to EDDL (