Lighthouse PLCs, Inc.Step up to the
A technical approach to a successful upgrade.
By Timothy Davis
Lighthouse PLCs, Inc.
Table of Contents
UPGRADING
FROM HITACHI “E”/”EB” SERIES TO HITACHI “EC” SERIES
Hitachi Japan Ltd. produced the “E-Series” from 1986 to 1995. As well as being sold under the manufacturers label, it was also sold as Reliance Electric Shark X, and under one or two other labels from Europe and around the world. Because its features were attractive to Original Equipment Manufacturers (OEM) as well as End-Users, this PLC enjoyed a high degree of success. In May 1987, eleven additional commands were added to the repertoire of the “E”. Current software addresses these units as “E2”. This upgrade added some arithmetic functions, functionality for “word” handling, and BCD to BIN conversions. In the mid-1990’s, due to changes in technology, changing user requirements, competition and Hitachi’s philosophy of always producing the “best in class” products, the decision was made to phase out the “E”. The proposed replacement became the “EB” series. The trend in the PLC industry in the late 1980’s was toward “flat-pack” units. Although the mounting depth requirement was reduced in these units, the actual “footprint” was as large or larger than their predecessors. This was not a forward step for the OEM’s. Plus, once again there was a surge in technology. As a result, the Flat-Packs gave way to more conventional “brick” style PLCs. The “EB” was produced from 1990 to 1995. The successor to the “E” & “EB” is the “EC” series. This new small brick was an immediate success from its introduction in 1993. As well as being sold under the Hitachi label, this unit has been sold in the United States as the Furnas Electric 96M series, and as Atlas Copco in Europe. With immediate access to one of the best semiconductors manufacturers in the world (Hitachi Semiconductor - whose components are even used by some competitor names you would recognize), it is not too surprising that when an even better processor became available, that Hitachi would put it into the “EC”. The “EC2“ (introduced in 1998) has doubled its processor speed! Of course that means your scan time has been cut in half! [Top]
Upside : Because of “backward” compatibility, the program running in your “EB” will work in the “EC/EC2” with little or no modification whatsoever. The program running in your “E” series will also work in the “EC/EC2” - with slight modification. [1] So, without having to “re-invent the wheel”, the program that has been controlling your machine or process can continue to serve you in it’s new host PLC! Win, Win, Win! The down-time involved in upgrading is generally much less than converting to a different brand PLC. Plus, no big fees from OEM upgrades or Integrators, and you enjoy the same dependability you have come to expect with Hitachi brand PLCs! Another point in favor of upgrading to “EC2”, is the additional capabilities of this unit. As previously mentioned, the backward compatibility insures that all the “functions” you used in your “E” are still available. And, you get 4 additional basic commands, and 25 additional Applications and Arithmetic Instructions. All there for your use should you decide to optimize your process.
Downside :
Starting with the “EB”, there were some changes made to
the way the I/O addressing was handled. 1st
- The “E” inputs were numbered from 000 thru 007, 008 & 009 were
skipped, and continued on from 010 up to the maximum number of inputs in the
same fashion. (This is typical for octal based units of this era, regardless of
manufacture.) This is generally not a big issue - solved by just re-numbering
some input wiring (Don’t forget to update your documentation.)
2nd - The outputs were readdressed - instead of
starting at 50, the “EB”, “EC” and newer all start at 200 (more closely
matching their bigger brother the EM/EMII series
card and rack style PLC). Simply
re-numbering the output wiring solves this.
There were also some changes in the internal volatile and non-volatile
memory locations. These are more
often consider nuisance items, rather than a big issue, as the Programming
Software makes it very easy to “re-allocate” the I/O (instructions included
in the software).
If you do
not have the software, be prepare for some long hours and tedious work.
Your next option of course is to hire an outside source that does have
the software, and let them perform this work for you.
This is a cost effective alternative unless you or your management
don’t consider your time (or your
PLC technician’s time) to be of any value.
[Top]
1.
The “E” processor ran at 5µS/word in average (basic command).
The “EB” ran at 3µS/word (167% increase). The “EC” can execute
a word in 1.5µS (333% increase in processing speed).
The “EC2” processor approaches 0.75µS/word (request Document
NJI-194X for a complete discussion on the “EC2” processor speed benefits).--
So What? What does it mean to us if the “EC2” has nearly 666% increase in
processing speed??? If you have ever been involved in the ongoing debate about
“real-time” issues, you know that the big drawback to digital processing in
an “analog” world is that only one thing happens at a time.
In the simplest terms, supposed you have a switch connected to a relay.
As soon as that switch is closed, the electrons close the distance between the
switch and the coil and whoosh! - the electromagnetic field starts to develop
to pull the armature of the relay down to make the contacts change state.
This is actually pretty slow when you are used to working in the
digital world, but it seems to happen almost instantaneously.
But in the digital world, the Input that the switch is connected to is
only looked at once each scan. Restating,
that may be like a few nano-seconds out of every ten milliseconds.
Not a big problem if you only have push buttons and
mechanical limit switches on your
machine. But what if you have
photoelectric sensors on a
high-speed conveyor, or an inductive proximity switch looking
at the key on a motor shaft rotating at 3600 RPM?
The more often the processor is looking at that input, the less likely
you will experience an error! So
faster is better! Is there ever a
situation where this is not true? Unfortunately, yes.
Supposed you have an old push-button and the spring inside is getting
weak. Instead of holding the
contacts firmly together when the Operator is pushed or released, the spring
allows the contacts to “chatter” or bounce.
A very fast processor may scan this input so fast that it reads each
bounce as a separate input signal. This
could cause your process or machine to behave strangely.
The most straightforward fix for this would to simply add a DIF
(Leading Edge Detection) or a latching circuit to the input. Most programmers
consider this a small sacrifice for the benefits obtained with the faster scan
times! [Top]
One other
item worth mentioning is that some programmers in the past used the scan time
as a basis for a timer. Reducing
the scan time in this type of circuit could conceivably produce unstable
results. The solution obviously,
is to change this inappropriate (or more accurately, antiquated) programming
method to a more standard (i.e. stable/accurate/repeatable) time base.
The EC/EC2 provides special memory locations (Bits 962 thru Bit 991)
just for this purpose.
2. The “E”-Series, like its predecessor - the “J”-Series, had no internal or on-board serial port. The “EB” series HR(P) and SR(P)models also had no on-board serial port. The “EB” CR(P) does have a serial port. A serial interface module named “PIF-J” (no longer available) allowed PC communication to the “E” and “J”. Most people however, simply used the PGM-JR2 “Universal Programmer” for communications to an (IBM) PC. The PGM-JR2 is a multi-function tool, which, among other things, acts as a “protocol converter”, allowing you to cable directly from the DB25M port to your PC serial port. The good news is that the “EC/EC2” does have an on-board serial port (RS232C - 8 pin DIN). Your PGM-JR2 will still work with an adapter (CNPG-15). [Top]
Upgrade
Analysis (or... How to
avoid Potential Pitfalls) :
Most upgrades take place without incident.
This is especially true when upgrading from “EB” to “EC/EC2”.
A successful upgrading does involve a couple of steps.
1.
Output Voltages. The first thing we recommend for you to do
when considering any upgrade is to analyze the outputs of your existing
units. If your older Hitachi PLC
had transistor output, you probably should stay with transistor outputs.
If your unit had relay outputs, as most do, you must avoid a potential
pitfall. Except in the case of
the “E-20HR(P)” which had a separate and unique “common” for each
output point, all other “E” Series PLCs have outputs grouped into
sections, each section having its own common.
This is done to (a) conserve terminal space, and (b) provide a way to
bring multiple voltage sources into
the PLC, without having to use interposing relays.
An example would be if your machine had 24VDC coils on the relays and
contactors/motor starters, but had 120VAC solenoids as well.
By utilizing this grouping of commons, you could conceivably run both
voltages through the PLC. So, the
obvious caution here, is to make sure that IF you have more than
one voltage source on the relay output of your existing PLC, that there is
sufficient number of outputs per common to accommodate your needs.
Worst case, you may have to go to the next size larger unit, or resort to a
few interposing relays. [Top]
1.A.
If your exiting PLC was a 64 I/O unit (or
had an expansion unit) - read this! The
“E” and “EB” series PLCs came in 20, 28, 40, and 64 I/O
configurations. The “EC/EC2”
comes in 20, 28, 40, and 60 I/O. So,
if you had more than 36 inputs and/or 24 outputs, the “EC/EC2” will not
work as an upgrade for you. These
newer units do not have the capability for an expansion module, as the “E”
/ “EB” did, so there are no expansion modules available for you to add on.
There is still a solution however!
The EMII series is a “card and rack” system.
This means you can build up whatever configuration you need to
accommodate your needs. And, your
“E/EB” program can be converted (same processes) to work in the EMII.
Contact us for more information or assistance.
2.
Maximum Output Load.
The “EC/EC2” is considerably smaller than the “E” or “EB”.
Smaller relays were used as part of this size reduction.
If your facility power utility has a good power factor (COSŘ=1) you
could draw 2 amps across a single output on an “E” or “EB”.
If your utility power factory was less, (for example COSŘ=0.4),
Hitachi says you should only be
drawing 1 amp across a single output. (See
Figure 1 below).
Figure
1 Relay Output
Specification
The
Operation Manual for the “EC/EC2” specifies 1 amp per circuit - to a
maximum of 4 amps per 6 circuits (utilizing 1 common).
It is therefore our recommendation that before you convert (to any PLC)
you should measure the operating current of each output to determine the
current draw. If your system
requires more than the “EC/2”[2]
allows you will have to put in interposing relays -(i.e.
an intermediate relay like an “ice-cube” or general purpose relay)
- which can handle the required load.
[Top]
3.
Inductive Load.
All new (regardless of brand) PLCs are somewhat more susceptible to
transient voltage than the older units. This is because the process of
miniaturization results in smaller distances between tracings on circuit
boards. As the distance
decreases, the ability for transient voltages to arc across increases.
Also the EEPROM and other
semi-conductors have more susceptibility to static electricity and other
transient voltages. This simply
means that if your facility power is “dirty”, you should consider TVSS (Transient
Voltage Surge Suppression) and Power Filtering in
front of the PLC. Also, you
should consider Surge Killers and
Flywheel Diodes for your inductive
loads, as shown below.
Figure 2 Example of Output Circuit
HARDWARE
You have read the Upgrade Analysis, and learned how to Avoid Potential
Pitfalls. You are now ready to
start the upgrade installation. Here
is how to proceed.
For comparison, and ease of understanding, wiring
diagrams from both PLCs are presented below.
Hitachi “E” series PLC with PGM-J Hand-Held Programmer
Figure 4 E Series Wiring Diagram
NOTE:
The procedure described above provides a “source” type input (NPN).
Use the above procedure for all switch (pushbuttons, limit switches,
etc.) applications, and most (U.S. ) NPN devices.
If however, your input device is (PNP) Sinking, then jumper from 24V
(+24VDC) terminal to “Common” instead of the method described earlier. [Top]
Figure 5 Hitachi EC2-20HRP
SOFTWARE
Now that the “hardware” considerations have been taken care of, we
now turn our attention to the “software” side.
A decision now must be made on how to accommodate the readdressing of I/O
as mentioned previously. If you
already possess Programming Software from Actron A.B., then the choice is
simplified for you, as ActSip contains
a text file that outlines the steps to take.
If on the other hand, your company only possesses one of the three
available hand-held programmers (such
as the PGM-J show in the picture of the “E” series) then you must accomplish
this task manually. If your
facility does not have people who possess the “Technical Know-How” to
perform this task, you should seriously consider having an Integrator or someone
like Lighthouse PLCs, Inc. do this for you.
The program contained within your “E” series is copied, the I/O
reallocated, and then re-inserted into the “EC/2”.
One other advantage of having this process done via the Actron
Programming Software is that you can get a complete set of documentation as a
by-product of this conversion. This
documentation will show your project (the program that runs inside your PLC) as
Ladder Logic, or Instruction Set. Ladder
Logic is the PLC equivalent of RLL (Relay
Ladder Logic) that most Western Electrician use.
Instruction Set is the keystrokes you would use to enter the program via
a hand-held programmer (only the largest hand-held programmer, the PGM-GPE2 allows
Ladder Logic programming). This
documentation is extremely valuable as a troubleshooting aid, or for machine
diagnostics. To make this document
as complete and comprehensive as possible, the text file contained within the
Actron ActSip Programming Software is
presented in the Appendix.
[Top]
SUMMARY: Presumably, you are replacing a “J”, “E”, or “EB” unit that has been performing some task or operating some piece of machinery in your plant or facility. More than likely somebody spent a goodly amount of time, energy, and resources to make your system work, and work well. Your Hitachi PLC has been a good investment, and has made you money. To maximize your investment, and build success upon success, you have chosen wisely in upgrading to a new Hitachi unit. The EC2 is a real workhorse, built on the success of its predecessors, back prior even to the “J”-Series, to the “D” series. There has been untold man-hours devoted to the development of this PLC. By sticking with a “known commodity”, and by virtue of being able to “reuse” the costly development that went into the original investment, you have made a wise choice. By paying attention to a few simple conditions, this upgrade should serve you well for a long time to come. Congratulations, and Thank You for letting us be part of your success! [Top]
(E-EM.ENG
text file from the ActSip-E Programming Software)
Translating
a project from Hitachi series E to
Hitachi series EB (including EC and
EM/EMII)using Actsip-E.
--------------------------------------------------------------------
You
can be in different starting positions
A
- The project is on the computers disk
Load the project from the disk with
"Files-Load project"
Continue with the printout of cross-reference below
B
- Project is in the PLC system
Select PLC type Series E2
Fetch the project to the computer with the menu selection
"Communication-From PLC"
Save the project on disk with "Files-Save
project"
Print
a cross-reference list for later use with "Printout-Cross
reference".
Now
select new PLC type in "Setup-PLC" (either type EB, EC, EM, EM2 or
EM3).
Now
do the given moves specified below with the menu selection
"Allocation-Move".
(First number is "From:" and second digit
(after
the arrow) is the "To:" and the last number is the
"Count:".)
Please
note that the order that you do these moves is important! They
should
be performed in the same order as given here.
Always
do the following moves:
584->960,8
965->969,1
320->700,250
(On the CPM-E3 move on 240 because of the real time clock.)
160->400,128
If
an EZ expansion module is used:
128->300,24
120->140,8
100->120,16
80->100,16
If
the old system uses POJ or PIJ modules, do the following:
If
the position is an POJ-module
PIJ-module
8e:
150->368,8
150->168,8
7e:
140->360,8
140->160,8
6e:
130->348,8
130->148,8
5e:
120->340,8
120->140,8
4e:
110->328,8
110->128,8
3e:
100->320,8
100->120,8
2e:
90->308,8
90->108,8
1a:
80->300,8
80->100,8
Then
always do the following move:48->200,24
Now
all the addresses have been moved to EM/EB addresses.
Save
the project under a new name and print the cross-reference list
And
compare it to the original cross-reference list printed above.
If
the project contains FUN30-FUN39, these must be translated manually.
To
check for other problems do a "Program-Syntax check".
Now the project is translated. [Top]
64 I/O unit..................................................... 4
AC Input Wiring............................................. 7
Actron ActSip Programming Software.... 11
ActSip............................................... 8, 11, 12
Atlas Copco.................................................. 1
digital processing......................................... 3
E Series Wiring Diagram............................ 9
E2............................................................ 1, 12
EB.................................... 1, 2, 3, 4, 5, 12, 13
EC........................... 1, 2, 3, 4, 5, 7, 8, 11, 12
EC2........................................ 1, 2, 3, 4, 5, 10
EC2 Wiring Diagram................................. 10
EEPROM...................................................... 6
EM/EMII................................................... 2, 12
E-Series........................................................ 1
Flat-Packs..................................................... 1
Flywheel Diodes........................................... 6
Furnas Electric.............................................. 1
96M series...................................... 1
hand-held programmers............................ 11
History............................................................ 1
Hitachi........................................ 2, 4, 5, 8, 12
Hitachi “E” series PLC............................. 8
Hitachi Japan Ltd......................................... 1
Hitachi Semiconductor................................ 1
inductive proximity switch............................ 3
Input Wiring................................................... 7
Input/Output Addressing.............................. 8
Instruction Set............................................. 11
Integrators..................................................... 2
interposing relays......................................... 5
Ladder Logic.............................................. 11
Leading Edge Detection............................. 3
limit switches............................................ 3, 9
Maximum Output Load............................... 5
multiple voltage sources.......................... 4, 8
NPN............................................................... 9
OEM. See Original Equipment Manufacture
Original Equipment Manufacturers............. 1
Output Voltages........................................... 4
Output Wiring................................................ 8
PGM-GPE2................................................ 11
PGM-JR2......... See Universal Programmer
photoelectric sensors................................... 3
PNP............................................................... 9
Power Filtering............................................. 6
processor speed...................................... 1, 3
Programming Software from Actron A.B. 11
push buttons.................................................. 3
Relay Ladder Logic................................... 11
Reliance Electric.......................................... 1
RLL........................ See Relay Ladder Logic
Shark X.......................................................... 1
Sinking............................................ See PNP
SOFTWARE.............................................. 11
source.............................................. See NPN
Surge Killers................................................. 6
Transient Voltage Surge Suppression....... 6
TVSS See Transient Voltage Surge Suppression
Universal Programmer................................. 4
Actron
A.B., Actron ActSip-E, Atlas
Copco, Furnas Electric, Furnas 96M Series, Hitachi Japan Ltd., Hitachi
Semiconductor, Lighthouse PLCs, Inc. Reliance Electric Co., and Reliance Shark
X/XL” are registered trademarks of their respective companies.
All rights reserved.
All
rights reserved under International Pan-American Copyright Conventions.
No part of this publication may be reproduced, stored in a retrieval
system, or transmitted in any form or by any means, electronic mechanical
photocopying, recording, or otherwise, without the written permission of
Lighthouse PLCs, Inc.. [Top]
Lighthouse
PLCs, Inc. website is http://www.lighthouseplcs.com
Author’s
Bio
Timothy
R. Davis is President and founder of Lighthouse PLCs, Inc.
He has authored many technical papers and Industry Newsletter articles
during his 30-year career. Mr.
Davis holds Master Electrician licenses for the states of Colorado and
Wyoming, and a Journeyman Electricians license in the state of Oregon.
He has written course material and conducted Electrical Apprentice
training courses in a half dozen Western states.
Mr. Davis drafted the Electrical Construction Standards for Plants
& Stations Engineering Construction for a major natural gas pipeline based
on the then current National Electrical Code, Instrument Society of America
(ISA) Standards & Practices, and American Petroleum Institute (API)
standards, which is still in use today. Timothy is an active member of the
International Association of Electrical Inspectors (IAEI) and a Senior Member
of the Instrument Society of America (ISA), memberships in both since 1981.
He has been certified as an Inspector by the American Society for
Testing and Inspection (ASTI). Timothy also taught courses in Instrumentation
Technologies to Continuing Education Students from 1978 to 1983, utilizing his
Colorado Vocational Teachers Credential.
Mr. Davis has a Diploma in Business Management.
He has been happily married for the past 24 years, has two married
sons, and two daughters attending the University of Oregon.
Having attended the Interlochen (MI) Arts Academy studying classical
music as a teen-ager, he still enjoys playing the piano and organ and enjoys
his cat named “Phydeaux” (pronounced FIDO). [Top]
Document
#36860
Ver. 5
Last Revision 11/30/2000
[Top]
[1] Lighthouse PLCs, Inc. has worked with Actron A.B. to produce a conversion process to upgrade the Hitachi “J” series (the predecessor to the “E”-series) to the “EC2”. See us for details.
[2] The designation “EC/2” is intended to mean either the original EC, or the improved EC2.
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