Spectrum-controls 1734sc-IE2CH Manuel d'utilisateur télécharger pdf (Page 47)

Chapter 4: IExCH and HART 4-7

User’s Manual Pub. 0300257-01 Rev. A

notify the user when to send the Get HART Device Information message to retrieve the

cached data. See Table 3-4 and Table 3-5.

Table 4-6 (HART Refresh Sequence)

Commands sent to re-fresh Device Information on Configuration Change Detected

Command: Definition: Comment:

38 Reset Configuration Changed bit

12 Read Message

13 Read tag, descriptor, and date.

15 PV upper and lower range values

16 Read final assembly Number.

48 Read Additional Device Status

50 Read dynamic variable assignments.

The following table describes the class, service code and instances required to send the

Get HART Device Information message.

Table 4-7 (Get HART Device Information)

Unconnected Message

Field Value Definition

Message Type “CIP Generic”

Service Code 0x4D Get Device Information

Class Name 0x035D HART Object

Instance Name 1-4 Selects channels 0 through 3

Object Attribute None, leave this field blank

Request Size 0 No Request Data

Reply Size 2-120 bytes

(2) Size when Device information not

available

(120) Size when valid Device

Information returned

Number of Data bytes

returned

The following tables describe the possible message responses.

Table 4-8 (Request Data)

HART Get Device Information - Request packet structure

Get currently cached Device Information for a given channel.

Offset Field Value Definition

No Request Data

1 2 ... 42 43 44 45 46 47 48 49 50 51 52 ... 83 84

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Spectrum-controls 1734sc-IE2CH Manuel d'utilisateur Page 47