GE 90-30 PLC Series Installation And Hardware Manual page 119

5
EPROM and EEPROM User Program Storage Options
The Model 311, 313, 323, 331, and an earlier version of the Model 341 CPUs have a User PROM
option for storing user application programs, register data, and configuration data in non-volatile
memory. Application programs are usually developed in a CPU's battery-backed RAM memory
and executed from this RAM memory. But, if additional program integrity, or operation of the
PLC without a battery is desired, an optional EEPROM or EPROM can be installed in a spare
socket (labeled PROGRAM PROM) on the embedded CPU baseplates or in a socket inside the
Model 331 CPU module (and inside the early versions of Model 341 CPU prior to hardware
version IC693CPU341-J and firmware release 4.61). The Model 331 CPU module (and the early
versions of Model 341) has a jumper labeled JP1 located next to the EEPROM/EPROM socket to
allow you to select either EEPROM or EPROM. These jumper positions are shown below.
Comparing EPROM and EEPROM Features
For one-time applications, an EEPROM is the more practical of the two. It can be created in the
PLC itself and doesn't require any additional outside equipment. An EPROM is not as convenient
to create. It must be created outside the PLC using an EPROM burner. Because an EPROM is less
expensive than an EEPROM, if you need to reproduce multiple copies of a program to use on a
large number of identical controls, it may be cost effective to use EPROMs, especially if you
already have an EPROM burner.
5-8 Series 90-30 PLC Installation and Hardware Manual – August 2002
IC693CPU341-J
This tells us that the module has a revision level J. Later CPU modules are produced with two
revision letters, such as:
IC693CPU351-EK
The first letter stands for the hardware revision level and the second for the firmware revision
level.
These letters can be cross-referenced to the firmware version. A revision history list for Series
90-30 products, including CPUs, can be found in the GE web site technical support area
(www.ge-ip.com/support) that cross-references revision letters, firmware versions, and
related features. Also, if you have access to the progression of IPIs that were issued for the
particular CPU (these are available on the GE PLC InfoLink CD-ROM) you can find
the desired cross-reference. Of course, you can also contact your distributor or GE for
help.
If your firmware has been upgraded in the past, a small label that comes in the upgrade kit
should be attached to the side of the module next to the module identification label to indicate
the current firmware revision level. However, the label could have been forgotten; so to be
sure, you may want to read the information from the CPU with a programmer as described in
the "Direct Method" above. On models with EPROM firmware, the firmware revision level
will also be printed on the EPROM.
3 - 2
Jumper Selects
EEPROM
2 - 1 EPROM
GFK-0356Q