Reset Display
Format: 1B 01
Returns: xx yy zz
•where xx is the Microcontroller status:
−00 = OK
If a failure occurs, testing halts, and the firmware begins executing a loop as described in the Internal Power UP Diagnostics section in the Installation chapter.
•where yy is the External Character PROM status:
−00 = Not present (Always 00 for LCD)
−01 = OK, present
−FF = Failure
•where zz is the number (in hex) of character sets available in the External Character PROM
−00 = 10 (Always 00 for LCD)
Description: This command executes the power‐down power‐up diagnostic sequence. The communication lines (CTS for serial, BUSY for parallel) are placed in an exception condition (see the Internal Power UP Diagnostics section in the Installation chapter). The Microcontroller test consists of a check‐sum test on the ROM and a write/read test on the RAM. A check‐sum test is also performed on the External Character PROM that holds any user‐defined characters sets (This does not apply to the LCD).
After executing the command, the three status bytes (see above) are sent to the host, the display screen is cleared, the cursor moves to the 0 position, communication line exception conditions are cleared, and all registers and variables are initialized. Note that the screen is cleared during this command. If a host needs previous data redisplayed, the host must resend the previous data after this command has completed.
