Spectrum 1734, Руководство пользователя

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4-4 Chapter 4: OE2CIH and HART
User’s Manual Pub. 0300272-03 Rev. B
Table 4-1. HART Initialization Sequence
Commands sent at Initial Device Connection
Command: Definition: Comment:
0
Read Unique Identifier Associated
with Tag
Sent using Short Address to find device
6 Write Polling Address Only sent if device responded at non-zero
Addr
59 Write Number Of Response
Preambles Selects a minimum number of preambles to
be sent by a device before the start of a
response packet.
12 Read Message
Reads the message contained within the
device.
13 Read Tag, Descriptor, Date Read the tag, descriptor, and date contained
within the device.
15 PV upper and lower range values Reads the Primary Variable Alarm Selection
Code, Primary Variable Transfer Function
Code, Primary Variable Range Values Units
Code, Primary Variable Upper Range Value,
Primary Variable Lower Range Value,
Primary Variable Damping Value, Write
Protect Code, and Private Label Distributor
Code associated with the device or the
Primary Variable.
16 Read Final Assembly Number Read the Final Assembly Number
associated with the device.
48 Read Additional Device Status
Returns transmitter status information not
included in the response codes.
50 Read Dynamic Variable Assignments Responds with the Transmitter Variable
numbers that are assigned to the Primary,
Secondary, Tertiary, and Quaternary
Variables
3 or 9 Read Dynamic Variable Assignments Command 3 if HART rev 5; otherwise,
Command 9 is used
2 Read Loop Current Only sent if Cmd 9 is being used
If any information within a device is changed, the device sets its
Configuration
Changed
bit (bit 6 of
Field Device Status
byte), which is detected by the module.
The module then automatically resends the appropriate HART commands to
refresh this set of data stored in the module. The first command sent is Command
38 which will reset the ‘configuration changed’ bit in the device. An Input tag
status bit in the module is used to indicate that the device information has
changed. The user may examine this bit and resend the CIP message to get the
latest device information.