Siemens SIMATIC TI555 User Manual

5-5
Using an EEPROM or EPROM
TI545/TI555 System Manual
5.2 TI545/TI555 Memory and Mode Status at Power-up
When you power up a TI545/TI555 system, the CPU checks the status of the
EEPROM (EPROM) and the battery . A clear (un-programmed) EEPROM
(EPROM) is equivalent to having no EEPROM (EPROM) installed.
T able 5-3 lists mode and memory status (after power up) that result from
various battery and EEPROM (EPROM) conditions.
T able 5-3 TI545/TI555 Mode and Memory Status After Power -up
Conditions Results
Battery
Status
Programmed
EEPROM (or EPROM)
Installed and Selected
Controller Memory
Controller
Mode
Bad or Off No Cleared PROGRM
Bad or Off Yes
Cleared, then loaded with
program that is in
EEPROM (EPROM)
RUN
Good and
On
No No change
Mode prior
to power
loss
Good and
On
Yes (same program) No change
Mode prior
to power
loss
Good and
On
Yes (different program)
Cleared, then loaded with
program that is in
EEPROM (EPROM)
RUN

Siemens SIMATIC TI555 Specifications

General

Brand	Siemens
Model	SIMATIC TI555
Category	Controller
Language	English