Specifications

Command Descriptions 73
Acknowledge ('a')
Function: Verifies that a command was received by the controller and no
errors are pending.
0 1 2 3 4 5 6 7
Query: 'a'
Set: This command cannot be set.
0 1 2 3 4 5 6 7
Response: 'A' X X X X
An Acknowledge response is automatically sent to the host following each
command received by the controller (with the exception of the Hard Reset and
Quiet-all commands). Command-related errors are indicated in the Acknowledge
response in the X positions. A query is not necessary to acknowledge the
processing of a command.
However, an Acknowledge query is issued to retrieve any pending warnings that
were not related to a command, indicated by the Warning-pending bit in the Touch
packet. An Acknowledge query may also be used to interrupt a pending process
(such as a calibration sequence).
The Acknowledge response contains any pending error codes (up to four), where
any pending warnings appear in the positions denoted by the X's. The possible
errors are given in the following table in both ASCII and hexadecimal notation.
Error Value Meaning
'0' 00h No warning
'1' 31h Divide by zero
'2' 32h Bad input packet
'3' 33h Bad input checksum
'4' 34h Input packet overrun
'5' 35h Illegal command
'6' 36h Calibration command cancelled
'7' 37h Reserved (contact Elo)
'8' 38h Bad serial setup combination
'9' 39h NVRAM not valid - initializing
':' 3ah Reserved
';' 3bh Reserved
'<' 3ch Reserved
'=' 3dh Reserved
'>' 3eh Reserved
'?' 3fh Reserved