Spectrum Controls 1734sc-IE2CH User Manual

Page 54

4-14

Point IO™ 2/4 Channel Analog HART Module

User’s Manual Pub. 0300257-01 Rev. A

4.3.4

Flush Queue

The Flush Queue message can be sent to have the IExCH module discard any pending
HART replies awaiting a query command. These replies are automatically discarded
once the handle timeout period has expired. The handle timeout period is defined in the
module configuration. The default value assigned by the AOP is 20 seconds. Unless you
need to discard the replies faster than 20 seconds, you won't need to use this Flush Queue
command.

The following table describes the class, service code and instances required to send the
Flush Queue message.

Table 4-18 (Flush Queue)

Unconnected Message

Field

Value

Definition

Message Type

“CIP Generic”

Service Code

0x50

Flush Queues

Class Name

0x035D

HART Object

Instance 0-3

0 = All Channels
1-4 = Single Channel (0-3)

All channels at once or a single channel

Object Attribute None, leave this field blank
Request Size

No Request Data

Reply Size

Number of Data bytes returned

4.3.5

Suspend HART Communication

The “suspend HART communication" message, will temporarily suspend all HART
communication on one or more channels for up to 3 minutes. HART communication will
resume automatically under the following conditions:

•

After 3 minutes

•

If the HART configuration changes during the three minute timeout period

•

If the “resume HART communication” message is issued.

The following table describes the class, service code and instances required to send the
Suspend HART Communication message.

Table 4-19 (Suspend HART Communication)