Effect Of Poll Rate + Subscribed Points On Cpu Load - Honeywell CENTRA LINE EAGLEHAWK Installation & Commissioning Instructions

EFFECT OF POLL RATE + SUBSCRIBED POINTS ON CPU LOAD

The poll rate set for the EAGLEHAWK and the chosen number of subscribed points both make a demand on the CPU load. The
EAGLEHAWK has been verified to support the following scenario.
In this scenario, the EAGLEHAWK is controlling 6 AHU plants which are using CentraLine Macros.
In this scenario, the following is assumed:
▪ Each EAGLEHAWK is connected to one Mixed I/O Panel Bus module (with 34 points), with a normal poll rate (10s);
▪ There are 4 Modbus points, with a normal poll rate (5s);
▪ 10 Panel Bus and 4 Modbus points are in trend;
▪ 1 PX graphic with 38 points;
▪ 10 alarm extensions;
▪ 20 points have been exported to Niagara Supervisor;
▪ All points on the Supervisor are subscribed;
▪ All Modbus points are subscribed;
▪ One graphic is visible on the screen.
The following table provides information on the effect of the number of subscribed points and the poll rate upon the CPU load. In
all cases, it is assumed that the given bus is without control logic, alarming, or trending, and that it is the only bus running at the
EAGLEHAWK.
Table 20. Effects of poll rate and no. of subscribed points on CPU load
bus no. of subscribed points
Panel Bus
Panel Bus
BACnet MS/TP
BACnet MS/TP
C-Bus
NOTE: The CPU load should never exceed 80% on a continuous basis. The default load (with an empty station) is approx.
15%.
EAGLEHAWK CONTROLLER – INSTALLATION & COMMISSIONING INSTRUCTIONS
SUPERVISOR (20 points via FOX)
APPLICATION:
1 AHU WITH
CentraLine APPLICATION
Panel Bus
34 POINTS
Fig. 46. Example application
400 10 sec (normal)
400
400 10 sec (normal)
200
100
TRENDING:
14 POINTS
ALARMING:
10 POINTS
GRAPHICS:
1 PX PAGE, 38 POINTS
Modbus
4 POINTS
poll rate value change-time
1 sec (fast)
COV
COV
27
CPU load (approx.)
N/A 52%
N/A 71%
N/A 60%
20 sec 58%
15 sec 29%
EN1Z-1005GE51 R0216