The McQuayNetwork component includes the typical collection of slots and properties as most other network components. For general information, See “Common network components” in the Drivers Guide. The following sections provide additional details:
The McQuayNetwork has a Serial Port Config container found near the bottom of the property sheet, containing the following properties:
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Status — Either
{ok}or{fault}. -
Port Name — Enter the string for the
COMnserial port (RS-232) used on the host platform. For example, enterCOM2orCOM3. -
Baud Rate — Selected from a drop-down list. Typically, the default 9600 baud is used.
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Data Bits — Selectable as 5,6, 7, or 8 bits. Typically, the default 7 data bits is used.
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Stop Bits— Selectable as 1 or 2 bits. Use the default 1 stop bit.
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Parity — Selectable as None, Odd, Even, Mark, or Space. Typically, the default Even is used.
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Flow Control Mode — Do not select any flow control for OPM protocol.
As with most “fieldbus” drivers, the status of a McQuayNetwork is either the normal “ok”, or less typical “down” or “fault” (fault might result from licensing error, or if a non-existent COM port is assigned to Serial Port Config). The Health slot contains historical timestamp properties that record the last network status transitions from ok to any other status. The “Fault Cause” property further explains any fault status.
As in other driver networks, the McQuayNetwork has an available “Alarm Source Info” container slot you can use to differentiate
McQuayNetwork alarms from other component alarms in the station. See “About network Alarm Source Info” in the Drivers Guide for more details.
The McQuayNetwork’s monitor routine verifies child McQuayDevice component(s)—the “pingable” device in the McQuay driver. The default ping frequency is every 5 minutes, and is adjustable. For general information, see “About Monitor” in the Drivers Guide.
The McQuayNetwork has the typical network-level Tuning Policy Map slot with a single default Tuning Policy, as described in “About Tuning Policies” in the Drivers Guide. By default, only a single “Default Policy” exists, however, you can add new tuning policies (duplicate and modify) as needed.
If you have multiple tuning policies, you can assign McQuay proxy points as needed to different ones. Under any proxy point’s Proxy Ext properties, in its Tuning Policy Name property, select the desired tuning policy.
The McQuayNetwork has the typical Poll Scheduler slot, as described in “About poll components” in the Drivers Guide. It enables/disables polling, determines fast/normal/slow poll rates, and maintains statistics about proxy extension polls.
By default, a newly created McQuay proxy point uses the “Normal” poll rate. If needed, you can assign proxy points to different poll rates. Under any proxy point’s Proxy Ext properties, select the rate in its Poll Frequency property.
The McQuayNetwork has several “message handling” network-level properties common among serial drivers, described separately as follows:
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Retry Count — Determines how many retries the communications handler will try to send a message if the initial attempt is unsuccessful. For the OPM protocol, this should normally be set to 1.
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Response Timeout — Specifies the maximum time to wait for a response to a OPM message once sent. If a response is not received before this timeout, the OPM message is resent up to “Retry Count” times, each of which waits for this timeout period.
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Inter Message Delay — The minimum amount of time to wait between receiving a message on the McQuay bus, and sending the next request. This gives time for some McQuay devices to prepare for receiving messages again. Note that although setting this to a non-zero value has a negative impact on overall throughput, it may be necessary if a “slow-to-turn-around” McQuay device is on the network.
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Unsolicited Receive Handler — Contains a child “Unsolicited Message Count” property that tallies all unsolicited messages sent by the OPM. For informational use only.