TE Technology TC-24-25 - Manual (Page 30)

30
31. EEPROM WRITE ENABLE
Write Command: 34 hex
Read Command: 4c hex
Interpret: 0 is disable EEPROM writes
1 is enable EEPROM writes
Note: This function is always stored to EEPROM. This feature is
available for controllers whose EEPROM is revision D or later.
(The EEPROM has a white sticker on it labeled “C74-114D” where
the last letter indicates the revision level.)
Function Description: Upon a power-up or reset condition, the controller performs an
initialization of all command variables that have write commands by
transferring the last values stored in non-volatile memory
(EEPROM) to appropriately referenced static RAM locations. This
action is performed so that the controller can run faster (RAM is
faster than ROM). When the “EEPROM WRITE ENABLE” is
enabled, any changes in the run-time values of the command
variables are also stored in EEPROM as well in RAM and thus will
be recalled upon a power-up or reset condition. When the
“EEPROM WRITE ENABLE” is disabled, run-time values are
stored only in RAM. This setting gives you the ability to change
run-time values without changing your desired power-up settings.
This will also alleviate a possible problem since the maximum
number of writes to an EEPROM location is 1,000,000.
V. ASCII Reference Table
Dec Oct Hex Binary Description
000 000 00 00000000 ^@ ^` NULL NUL null c-@ c-`
001 001 01 00000001 ^A ^a SOH GTL c-A c-a start-of-heading
002 002 02 00000010 ^B ^b STX c-B c-b start-of-text
003 003 03 00000011 ^C ^c ETX c-C c-c end-of-text
004 004 04 00000100 ^D ^d EOT SDC end-of-transmission c-D c-d ..._._
005 005 05 00000101 ^E ^e ENQ PPC c-E c-e enquiry
006 006 06 00000110 ^F ^f ACK c-F c-f acknowledge
007 007 07 00000111 ^G ^g BELL BEL bell c-G c-g \a
008 010 08 00001000 ^H ^h BS GET backspace c-H c-h \b
009 011 09 00001001 ^I ^i TAB TCT HT tab c-I c-i \t
010 012 0A 00001010 ^J ^j LF lf linefeed c-J c-j \n
011 013 0B 00001011 ^K ^k VT vertical-tab c-K c-k \v
012 014 0C 00001100 ^L ^l FF ff formfeed page \f c-L c-l