AMETEK 7100 Leak Detect Stik - Manual (Page 5)

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1.2: Frame Protocol
All 7100 probes transmit data in the same general format. In this format, information is conveyed during a
discrete period of time called a frame. The duration of a frame varies depending on the probe type. Table 1
specifies the frame periods for various probe types.
7100 series probe data consists of a series of pulses that are transmitted along the wire pair that provides
power to the probe. Pulses are grouped in pairs called readings. Position and temperature information can be
determined by measuring the period between the two pulses that comprise a reading.
A frame consists of a sync. period followed by 15 readings. The sync. period is a period of time during which
no pulses occur. An external device that is attempting to synchronize with the probe data should start looking
for the first pulse in reading 1 after detecting a period greater than sync. period during which no pulses occur.
Table 1 lists the recommended sync period for various probe types.
Table 1 - 7100 Probe parameters by probe type
Probe Type Overall Length Frame Period Sync Period Reference Magnet
Types 1, 4
0 < L ≤ 18
72 ms 7 ms No
Types 2, 5 18 < L ≤ 24 144 ms 16.6 ms No
Types 3, 6 24 < L 144 ms 16.6 ms Yes
NOTE: Probe types 1, 2, and 3 are 5 thermistor probes (R5 designation in part number). Probe types 4, 5,
and 6 are 1 thermistor probes (R1 designation in part number).
Sync
Period
Frame Period
Read
ing 15
Read
ing 15
Read
ing 14
Read
ing 13
Read
ing 12
Read
ing 1
1
Read
ing 10
Read
ing 9
Read
ing 8
Read
ing 7
Read
ing 6
Read
ing 5
Read
ing 4
Read
ing 3
Read
ing 2
Read
ing 1
Figure 2: Data Frame Relationship Between the Data Pulses, Sync and Frame Periods
Figure 1: One frame of Data
Return to Start of Frame
16 Time Slots
#1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 #14 #15 #16
Pause
Temp #1
W
ater
Temp #2
Product
Temp #3
Product
Temp #4
Product
Temp #5
Product
Circui
t T
emp
Product Low Ref Product
High Ref