Unit Codes - Signet 9900 Operating Instructions Manual

Hart Commands
Universal Commands - Continued
Command 16 – Read Final Assembly Number
Returns the assembly number of the device. This will be defi ned by the customer. See Command 19.
Command 17 – Write Message
Write a message to be stored in the device. See Command 12.
Command 18 – Write Tag, Descriptor, Date
Writes the tag, descriptor and date values into the device. See Command 13.
Command 19 – Write Final Assembly Number
Writes the fi nal assembly number of the device. See Command 16.
Command 20 – Read Long Tag
Read the 32-byte long tag. The 'long tag' is separate from the 'tag' that is used in Commands 13 & 18.
Command 21 – Read Unique Identifi er Associated with Long Tag
Returns all identity information associated with the device - the device type, device revision level and Device ID.
Issued using the long tag.
Command 22 – Write Long Tag
Write the 32-byte long tag. See Command 20.
Command 38 – Reset Confi guration Changed Flag
Resetting the device's confi guration changes counter back to 0.
Command 48 – Read Additional Device Status
Returns extended device status information.
Supported HART Common Practice Commands
The following Common Practice Commands are supported.
CMD
Function
ID
40 Enter/Exit Fixed Current Mode
45 Trim Loop Current Zero
46 Trim Loop Current Gain
54 Read Device Variable Information
Command 46 – Trim Loop Current Gain
The 9900 will trim the gain of the loop current to match the loop current value sent to it.
This is typically performed at 20.00 milliamperes to optimize calibration.
Command 54 – Read Device Variable Information
Returns serial number, limits, damping value and minimum span for a selected device variable.

Unit Codes

The H COMM module uses standard HART Foundation Protocol 7.2 unit codes. The unit code allows the
HART Master to interpret and display the units of measure (e.g., GPM, PPB, °F, etc.) with two exceptions.
The following Unit Codes will not be interpreted by the HART Master:
Code Measurement Unit
240 Cubic Centimeters
244 Parts per Thousand
Command 40 - Enter/Exit Fixed Current Mode
The loop current of the 9900 is set to the value transmitted in the command
(in milliamperes). Setting a level of '0' exits Fixed Current Mode.
If the device is in Multi-Drop mode, Error Code 11 will be returned.
Command 45 – Trim Loop Current Zero
The 9900 will trim its offset of the loop current to match the loop current
value sent to it. This is typically performed at 4.00 milliamperes to optimize
calibration.
A HART Master will display these unit codes instead
of the units of measure that the code represents.
9900 Transmitter 69