Raw Data Commands

SUMMARY

The commands below can be used to communicate with any Humboldt HM-3000.  All commands will use a similar format for sending and receiving commands and data.

Typical Message Structure (bytes)

• Flag Byte
• 175 will always be the flag byte.
• Device ID
• 1 – 255
• Command
• Size
• Count of size of message starting with Device Id and ending with Checksum, this is not a checksum count.
• Data
• Checksum
• Addition of all bytes excluding Flag byte and checksum 0-255 wraps around if greater than 255.

HM3000 Raw Data Commands as of 02-25-2008

Start Raw Data

• Flag byte
• Device ID
• 3 ß Start Raw Data Command
• 4 ß Byte count
• Checksum

Start Raw Data Acknowledge (received after start raw data command sent)

• Flag byte
• Device ID
• 71 à Generic Reply Byte
• 21 à Message Size
• 3 àReplying Command (Start Raw Data Command)
• Byte 1 of Input 1 Tare Value (Floating point number)
• Byte 2 of Input 1 Tare Value
• Byte 3 of Input 1 Tare Value
• Byte 4 of Input 1 Tare Value
• Byte 1 of Input 2 Tare Value (Floating point number)
• Byte 2 of Input 2 Tare Value
• Byte 3 of Input 2 Tare Value
• Byte 4 of Input 2 Tare Value
• Byte 1 of Input 3 Tare Value (Floating point number)
• Byte 2 of Input 3 Tare Value
• Byte 3 of Input 3 Tare Value
• Byte 4 of Input 3 Tare Value
• Byte 1 of Input 4 Tare Value (Floating point number)
• Byte 2 of Input 4 Tare Value
• Byte 3 of Input 4 Tare Value
• Byte 4 of Input 4 Tare Value
• Checksum

 Stop Raw Data

• Flag byte
• Device ID
• 4 ß Stop Raw Data Command
• 4 ß byte count
• Checksum

Stop Raw Data Acknowledge (received after stop raw command sent)

• Flag byte
• Device ID
• 71 à Generic Reply Byte
• 5 à Message size
• 4 à Replying Command (Stop Raw Data Command)
• Checksum

Raw Data Message

• Flag byte
• Device ID
• 41 ß Raw Data Flag
• 14 ß Message size
• Byte 1 of input 1 raw data (unsigned integer)
• Byte 2 of input 1 raw data
• Byte 1 of input 2 raw data (unsigned integer)
• Byte 2 of input 2 raw data
• Byte 1 of input 3 raw data (unsigned integer)
• Byte 2 of input 3 raw data
• Byte 1 of input 4 raw data (unsigned integer)
• Byte 2 of input 4 raw data
• Limit up byte value (0 = True, 1 = False)
• Limit down byte value (0 = True, 1 = False)
• Checksum

NOTES: 

The Configuration values and the Calibration values are per channel and can be found in the Engineering screen of the equipment.

To determine channel value from raw data, use the following formula:

Raw Data to Engineering Data:

Slope = (Configuration Max – Configuration Zero) / (Calibration Max – Calibration Zero)

Value = (Raw Data Value – Calibration Zero – Tare Value) * Slope

Example:

Configuration Max = 2000.0

Configuration Zero = 0.0

Calibration Max = 32827

Calibration Zero = 6078

Tare = 0

Slope = (2000 – 0 ) / (32827 – 6078) = 0.0775584

Value = (6156 – 6078 – 0 ) * 0.077558 = 6 lbs