
ZENO
®
-3200 USER MANUAL
Coastal Environmental Systems (206) 682-6048
Page 9
2.3.1. RAM
Each ZENO
®
-3200 is shipped with a minimum of 256 kilobytes of static RAM.
10
The RAM is the
working memory in the ZENO
®
-3200. It is used to store the active configuration, the logged data records
and the internal data that is used by ZENOSOFT
®
to perform the operations necessary for the active
configuration.
Since the ZENO
®
-3200 is used in harsh environments, there is a possibility that there will be momentary
losses of power to the ZENO
®
-3200. Since RAM cannot maintain its stored contents during a power loss,
the ZENO
®
-3200 contains a small battery to maintain power to the RAM, allowing it to maintain its
contents during the power loss.
11
The battery used to back up RAM in the ZENO
®
-3200 lasts approximately 10 years. Eventually, it will
discharge to a point where it can no longer provide enough power for the RAM to be maintained during a
momentary power disruption and the data stored in RAM will be lost. It is for this reason that the second
type of memory, EEPROM, is used in the ZENO
®
-3200.
2.3.2. EEPROM
Unlike RAM, EEPROM does not require constant power to maintain its contents. Hence, the data stored
in EEPROM remains intact regardless of any power loss. The size of the EEPROM is very small, though,
in comparison to RAM. A Revision-A ZENO
®
-3200 will contain 2 kilobytes of EEPROM, but a
Revision-D ZENO
®
-3200 will contain 8 kilobytes of EEPROM.
Because EEPROM is a very safe type of memory storage, EEPROM is used by the ZENO
®
-3200 to store
the configuration. The ZENO
®
-3200 stores the configuration in a condensed format in the EEPROM
since it is much smaller than RAM.
ZENOSOFT
®
does not use the configuration stored in EEPROM during its normal operations because the
condensed configuration stored in EEPROM is not in a useable form.
12
One of the first things that ZENOSOFT
®
does when the ZENO
®
-3200 is turned on is to read and expand
the condensed configuration stored in EEPROM, then store the expanded (useable) configuration in RAM
for use during normal operations.
When you create a new configuration or modify an existing configuration, you are changing the
configuration stored in RAM, not EEPROM.
10
Formerly, the minimum amount of installed RAM was 64 kilobytes. Refer to Section 13.4 for the location of the
RAM on the main CPU board.
11
The battery acts like a miniature UPS, or Uninterrupted Power Supply, to the RAM.
12
This is analogous to a file that has been shrunk on a personal computer using a zip program.
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