If a driver error occurs during the form retrieval process,
the data acquisition software writes a text message, containing an error
return code in hexadecimal format, to your screen. This appendix contains:
- A driver error table
- Directions for converting the hexadecimal error
return codes written to your screen into the driver error codes shown
in the table
Converting error return codes
into
RS-232 driver error codes
To convert the hexadecimal error return
code into a driver error code, you must first convert the hexadecimal
number into a binary number and then look up the position number of
the bits that are on.
To convert the hexadecimal error return
code into a driver error code:
- Convert the hexadecimal error number on your
screen to a binary number. Binary equivalents for hexadecimal numbers,
in groups of four bits for each hexadecimal digit, are shown on the
next page.
Hexadecimal Equivalents
|
Hexadecimal
|
Binary
|
Hexadecimal
|
Binary
|
0
|
0000
|
8
|
1000
|
1
|
0001
|
9
|
1001
|
2
|
0010
|
A
|
1010
|
3
|
0011
|
B
|
1011
|
4
|
0100
|
C
|
1100
|
5
|
0101
|
D
|
1101
|
6
|
0110
|
E
|
1110
|
7
|
0111
|
F
|
1111
|
For example, in the following table, the error
number 85 (shown on the first line below) is the binary number 10000101
(shown on the second line).
Example Conversion
|
Hexadecimal error
|
8
|
5
|
Bit value
|
1000
|
0101
|
Bit position
|
7654
|
3210
|
In the binary number 10000101, each binary digit
is called a bit. A one means the bit is on, while a zero means the
bit is off.
The bit positions, reading from left to right,
are 76543210 (shown on the third line).
- Look at the last three bits on the
right (101 in the above sample). These bits are the completion code
that tells whether the command succeeded, or whether it failed and
why.
- Look up the completion code number in the RS-232
driver error table below. You will see that the error represented
by the value 101 is No DSR (line break).
Driver Errors
|
Bit Positions
|
Errors
|
Bit Type
|
2 to 0
|
Completion Code:
|
|
|
000 = Successful completion
|
|
|
001 = "Busy" or "no character ready"
|
|
|
010 = Parameter error
|
|
|
011 = Not opened
|
|
|
100 = Not closed
|
|
|
101 = No DSR (line break)
|
|
|
110 = No CTS (modem error)
|
|
|
111 = Illegal command
|
|
3
|
Overrun error
|
Receive only
|
4
|
Parity error
|
Receive only
|
5
|
Framing error
|
Receive only
|
6
|
Break detected
|
Receive only
|
7
|
Timeout indicator
|
|
- Notice whether a 1 is in any of the
bit positions 3, 4, 5, 6, or 7.
- Look up the corresponding bit position number
in the driver error table to obtain further error information.
For example, in the example conversion table
above, bit number 7 is on. If you look in the driver error table,
you will see that this number corresponds with Timeout indicator.
Of the completion codes, the only
one that should appear is 101 (No DSR). The DSR line in the interface
cable between the AUDIX system and the PC carries a signal that controls
the flow of data. When error 101 appears on your screen, this control
signal either is not present or is in the wrong state. None of the other
completion codes should be seen.
When the driver is opened, it is told
to ignore CTS (Clear to Send) errors.
Driver errors may be accompanied by
the timeout indicator.