Tyco MX4428 technical manual MIM801, MIM800

MX4428 MXP Engineering / Technical Manual	Document: LT0273
MXP Loop Filter Board

9.7MIM800 / CIM800 / MIM801 PROCESSING

The MIM800 and CIM800 return a value which depends on the external resistance across the contact terminals and which can be modelled by the equation –

VALUE = 226 * (150 + 3) / (150 + Rext + 3)

The MIM801 returns a value which depends on the external resistance across the contact terminals and which can be modelled by the equation –

VALUE = 226 * (Rext + 3) / (150 + Rext + 3) (unless Rext is open circuit, then value = 255)

(Note 150 represents an internal 150Ω resistor, 3 represents a 3Ω FET on resistance, and 226 represents (3.3V - DIODEV) / 3.3V * 255

Graphs of these values are show in Figure 9.7. Also shown are the default thresholds, and the interpretations of the input ranges between the thresholds.

	240
	220	N/O : Optional S/C Fault
	200
											N/O :
	180	176						MIM801			O/C Fault
	160		N/O : Alarm							170	N/C :
		N/C:									Alarm
							Normal
Reading	140	O/C Fault		122
	120
	100	N/O :		110
	80	Alarm					Normal						N/O :
		N/C : S/C Fault
	60							MIM800				50	O/C
		40											Fault
	40	N/O :											N/C :
													Alarm
	20	Optional S/C Fault
	0
	0	50	100	150	200	250	300	350	400	450	500	550		600
							R

Figure 9.7 MIM800 / MIM801 Reading versus resistance

The usual parameters are as follows –

		MIM800 / CIM800
	P0		P1	P2
No alarm resistor	122		50	0
(Default)
With alarm				176
resistor

P3

110

MIM801

P4 P5

1700

40

Page 9-10 24 March 2006 Issue 1.5