Pressure Systems, Inc. NetScanner™ System (9016, 9021, & 9022) User’s Manual
www.PressureSystems.com
3 - 6
The error response consists of the letter ‘N’ (for NAK, or negative acknowledge), followed by a 2-
digit hexadecimal error code. The following table lists the error codes that can be returned from a
NetScanner™ System module: Table 3.1
Error Codes
CODE MEANING
00 (Unused)
01 Undefined Command Received
02 Unused by TCP/IP
03 Input Buffer Overrun
04 Invalid ASCII Character Received
05 Data Field Error
06 Unused by TCP/IP
07 Specified Limits Inva lid
08 NetScanner error: invalid parameter
09 Insufficient source air to shift calibration valve
0A Calibration valve not in requested position
The Acknowledge response is returned from a module when a command is re ceived that requires no
data to be returned, and no error is detected. I t indicates successful parsing and execu tion of the last
received command. It consists of the letter ‘A’ (for ACK, or acknowledge).
The Acknowledge with Data response is returned when a module receives a command requesting
data. NetScanner™ System modules will typically return only the requested data values, each
preceded by a space character (except for format 7). No ‘A’ acknowledge letter begins this data
response. Data are returned for the highest requested channel number first.
3.1.3.1 Interpreting Offset Values (Re-zero Calibration Adjustment)
When a module is instructed to execute the command Calculate and Set Offsets (‘h’), a datum
corresponding to the calculated offset correction term (or coefficient) is returned for each affec ted
channel. Each such coeff icient value is stor ed internally, and will be subtra cted in a ll subsequ ently
calculated data conversions , to correct for zero drift effec ts. The command only re turns them in the
response (in current engineering units (EU) of pressure) to allow the user to make reasonableness
checks on them. The Read Internal Coefficients (‘u’) command will return them on demand.