Honeywell R0512 manual Broadcast Hysteresis, Intrinsic Hysteresis for Analog Input Signals

EXCEL 50/100/500/600/800 ATTRIBUTES

Broadcast Hysteresis

Broadcast hysteresis (V1.5.x) The attribute "Broadcast Hysteresis" is available for the datapoint type "Global Analog". The attribute "Broadcast Hysteresis" prevents new values from being broadcast to other controllers unless the datapoint value changes (positively or negatively) at least by the amount specified in the attribute "Broadcast Hysteresis". The minimum hysteresis value is 10-a(a = number of decimal places set in the attribute "Engineering Unit"), but not smaller than 0.2 (see also the example in section "Value Hysteresis" on page 35). The CARE default value (i.e. 1% of actual value and no less than 0.2) for this attribute is 0. Access to the attribute "Alarm Hysteresis" is also possible via RIA/WIA.

This value can be edited from an operator interface (XI581 [not with XCL5010, Excel 100C], XI582, XL-Online, and Excel 50 MMI) via the B port (XC5010C / XC6010) or the serial port (Excel 100C, Excel 500), the system bus (XBS 1.3.3 and higher and XFI 1.6.1 and higher), and CARE RIA/WIA statements. The password level for this attribute is determined by the "Access" attribute (default initialization value in CARE is 0). If several global points (remote points) are assigned to the same physical point, the lowest global point "Broadcast Hysteresis" value of all assigned global points is used.

Intrinsic Hysteresis for Analog Input Signals

A minimum default hysteresis of 37 mV (24 - 1 bit) for 0 to 10 V input signals is implemented. Due to the nonlinearity of NTC sensors, the hysteresis varies over the temperature range, whereas it is approximately constant for PT 100/1000/3000 and Balco 500 sensors. Approximations of hysteresis depending on the sensor and temperature range are summarized below.

NOTE The Intrinsic Hysteresis for analog input signals is not a user- programmable attribute, but rather an intrinsic hysteresis of the Excel 50/100/500/600/800.

NTC 20k Ω Hysteresis varies nonlinearly over the entire temperature range and depending on whether the upper boundary (MAX LIMIT) or the lower boundary (MIN LIMIT) is exceeded. The approximations shown in Table 8 can be used in practice (intermediate values can be interpolated):

	Table 8. Intrinsic hysteresis values for various temperature ranges
	temperature range	average hysteresis		average hysteresis
		MIN LIMIT		MAX LIMIT
	-40 °C (-40 °F)	2.2	K (4.0 °F)	2.5	K (4.5 °F)
	-30 °C (-22 °F)	1.3	K (2.3 °F)	1.3	K (2.3 °F)
	0 °C (32 °F)	0.4	K (0.7 °F)	0.4	K (0.7 °F)
	40 °C(104 °F)	0.5	K (0.9 °F)	0.4	K (0.7 °F)
	80 °C (40 °F)	1.5	K (2.7 °F)	1.5	K (2.7 °F)
	100 °C (212 °F)	3.0	K (5.4 °F)	2.7	K (4.9 °F)
	130 °C (266 °F)	8.5	K (15.3 °F)	7.2	K (13.0 °F)
PT 100 (not with Excel 100C)	Hysteresis increases approx. linearly with temperature.
	Average hysteresis:	0.75 K (1.35 °F)
	Hyst. At -45 °C (-49 °F):	0.7 K (1.3 °F)
	Hyst. At 145 °C (293 °F):	0.8 K (1.4 °F)
PT 1000/1	Hysteresis increases approx. linearly with temperature.
	Average hysteresis:	0.8 K (1.4 °F)
	Hyst. At -45 °C (-49 °F):	0.7 K (1.3 °F)
	Hyst. At 145 °C (293 °F):	0.9 K (1.6 °F)

23 EN2B-0092GE51 R0512