AMETEK 7100 Leak Detect Stik User Manual
TM
Interface Manual
Continuous Level Controls
7100
™
Leak Detect Stik
Magnetostrictive LeveL systeM
ABSOLUTE PROCESS CONTROL
KNOW WHERE YOU ARE... REGARDLESS
.
Contents
Chapter 1: Description of Probe .............................2
1.1 Data Protocol ....................................................2
1.2 Frame Protocol ...................................................3
1.3 Installation and Dimension Drawings ..................................5
Chapter 2: Interfacing to Probe..............................8
2.1 Interface Hardware ...............................................10
Chapter 3: Getting the Data................................ 12
3.1 Synchronizing with a Watchdog Timer ................................12
3.2 System Hardware Setup...........................................12
3.3 System Software Setup ...........................................13
Chapter 4: Processing the Data ............................14
4.1 Front End Algorithm ..............................................14
Chapter 5: Computing the Temperature ......................15
5.1 Improving Measurement Accuracy ...................................15
EC Certicate of Conformity ...........................................18
AMETEK has checked the accuracy of this manual at the time it was printed. Any comments you
may have for the improvement of this manual are welcomed.
AMETEK reserves the right to revise and redistribute the entire contents or selected pages of this
manual. All rights to the contents of this manual are reserved by AMETEK.
The information in this document is subject to change without notice. No part of this document may
be reproduced or transmitted in any form or by any means, for any purpose, without the express
written permission of AMETEK.
Chapter 1: Description of Probe
The 7100 liquid level probe uses a proprietary data transmission technique providing a compact information
format for level and temperature data, and a signal pattern which is very easily recognizable at the console.
1.1: Data Protocol
Transmission consists of a sequence of similarly formatted frames of data, each frame in turn, consisting
of 15 pulse pairs and a pause period. The pause period, as well as the 15 pulse pairs, each occupy 1 of 16
equal time slots of approximately 4.5 milliseconds¹.
Time slot #1 is the pause period and carries no signals. This pause is used by the console to synchronize
with the signal sequence. After this pause is found, no further recognition operations are necessary; the
console can simply follow the sequence described below. Each of the remaining 15 time slots carries two
pulses. The time interval between the pulses in each pair is equal to a value of the parameter assigned to the
corresponding time slot. (See Figure 1)
Even numbered pulse pairs #2, 4, 6, 8, 10, 12, 14, & 16 carry temperature related data.
The time interval between the pulses in time slot #3 is proportional to the water level (the lower oat position).
The six remaining odd numbered pulse pairs #5, 7, 9, 11, 13, & 15 carry signals related to the product signal.
Thus, information on the product level collected during one frame increases the initial resolution (determined
by the frequency of the clock advancing the high speed counters in the console) by a factor of about 2.5
(square root of 6). See footnote².
The entire message, including time slot #1 through
#16, is referred to as a Frame of data throughout
this document.
NOTE: The first pulse pair in a frame is in
time slot #2 and is hence referred to
as pulse pair #2. As stated above, the
eight even pulse pairs #2, 4, 6, 8, 10,
12, 14, & 16 carry temperature data. #2
through #10 correspond to the lowest to
the highest temperature sensors in the
probe rod, respectively. #12 corresponds
to the temperature sensor in the head
electronics. #14 and #16 are references.
The ve sensors are spaced apart equally
in the probe rod. (See Chapter 5 for more
information on computing the temperature).
¹ For probes over 18 feet in length, the frame duration should
be doubled. This is due to the longer wire propagation time.
² Since the magnetostrictive wire velocity is about 9
microseconds per inch, a 110 MHz. clock would provide a
single level readout resolution of 0.001”. Since the 7100 probe
utilizes the patented resolution-doubling reection method,
the resolution would be 0.0005”. If a more practical 40 MHz.
clock is used, the resolution is 0.001375”.
Input Voltage 16 to 31 VDC
Sensor Length
Enclosure Rating Material 316 SS or PVDF, IP 68
Typical Level Resolution
(Controller Dependent)
Linearity
Repeatability
Temperature Measurement Up to 5 along the sensor span
Temperature Accuracy, Absolute +/- 2°F
Typical Temperature Resolution
(Controller Dependent)
Temperature Sensing Range - 40°F to +158°F or -40°C to 70°C
Operating Temperature Range - 40°F to +158°F or -40°C to 70°C
Sensor Output Pulse Position Modulated
Distance to Monitor Over 1000’ using twisted pair wire
Floats (not included) Specs based on 4” standard oats
Approvals
Specications
Stainless Steel up to 24’
PVDF up to 70’
0.010” Inventory Mode
0.001” Leak Detection Mode
+/- 0.01% of Full Scale
+/- 0.010”, whichever is greater
+/- 0.001% of Full Scale
+/- 0.00025”, whichever is greater
+/- 0.01°F
NORTH AMERICA
CLASS I,II,III, DIVISION 1,
GROUPS D,E,F,G: T4 (7100 K&V)
GROUPS C,D,E,F,G,: T4 (7100 M&R)
Exia SECURITE INTRINSEQUE
EUROPEAN UNION IEC
CE 0575
II 1 G
Ex ia IIA T4 Ga (7100 K&V)
Ex ia IIB T4 Ga (7100 M&R)
IECEx UL 11.0041X
DEMKO 09 ATEX 0902049X
LISTED
14X7
Specications are subject to change without notice. Patented.
2
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
Water
Temp #1
Product
Temp #2
Product
Temp #3
Product
Temp #4
Product
Temp #5
Circuit Temp
Product
Low Ref
Product
High Ref
Figure 1: One frame of Data
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
species 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 rst 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
Types 2, 5
Types 3, 6
0 < L ≤ 18
18 < L ≤ 24
24 < L
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).
72 ms 7 ms No
144 ms 16.6 ms No
144 ms 16.6 ms Yes
Frame Period
Sync
Period
Reading 15
Reading 1
Reading 2
Reading 3
Reading 4
Reading 5
Reading 6
Reading 7
Reading 8
Reading 9
Reading 10
Reading 13
Reading 11
Reading 12
Reading 14
Figure 2: Data Frame Relationship Between the Data Pulses, Sync and Frame Periods
Reading 15
3
The type of information contained in each reading varies depending on the probe type. Table 2 species the data
pattern for various probe types.
Table 2 - Reading Data Type Specication by Probe Type
Types 1, 2, 3 Types 4, 5, 6
Reading 1 Temp 1 Temp 1
Reading 2 Product or Water* Product or Water*
Reading 3 Low Ref Temp Temp 2
Reading 4 Product Product
Reading 5 High Ref Temp Temp 3
Reading 6 Product Product
Reading 7 Low Ref Temp Temp 4
Reading 8 Product Product
Reading 9 High Ref Temp Temp 5
Reading 10 Product Product
Reading 11 Circuit Temp Circuit Temp
Reading 12 Product Product
Reading 13 Low Ref Temp Low Ref Temp
Reading 14 Product Product
Reading 15 High Ref Temp High Ref Temp
* For single oat probes, this frame contains product data.
For dual oat probes, this frame contains water data.
When calculating Water or Product positions, one must consider whether or not the probe uses a reference
magnet. For probes that use a reference magnet (type 3 and type 6), position can be calculated using the
following formula:
Position = Measured Period/Wire Speed
Where:
Measured Period = the time between pulses in a reading (ms)
Wire Speed = (ms / inch)
Position = distance from internal reference
For probes that do not use a reference magnet (types 1, 2, 4, and 5), position can be calculated using the
following formula:
Position = Measured Period/Wire Speed*2
4
1.3: Installation and Dimension Drawings
7100 Flex Stik Installation Drawing
5
Loading...