MTS Systems Level Plus STI User manual

lSensors Division
Level Plus®
Tank Gauging Systems
Side Tank Indicator (STI)
Installation & Operation Manual
0796 550436 Revision A

GENERAL INFORMATION
MTS PHONE NUMBERS
To place orders: 800-457-6620
Application questions: 800-457-6620
Service: 800-457-6620
Fax: 800-943-1145
SHIPPING ADDRESS
MTS Systems Corporation
Sensors Division
3001 Sheldon Drive
Cary, North Carolina 27513
HOURS
Monday - Friday
7:30 a.m. to 5:30 p.m. EST/EDT

Section TABLE OF CONTENTS Page
1.0 INTRODUCTION 1
1.1 Specifications 3
2.0 INSTALLATION 4
2.1 Mounting The Enclosure 5
2.2 Cable Requirements 7
2.3 Recommended Cable Types 17
2.4 How To Select Cables 21
2.5 Field Wiring Installation 30
2.6 Power Supply Requirements 34
2.7 Switch Settings 35
2.7.1 Default Setting 35
2.7.2 DIP Switch #1 36
2.7.3 DIP Switch #2 (Stand-Alone Mode — Commands/# of Gauges) 38
2.7.4 DIP Switch #2 (Network Mode — Address) 40
2.7.5 Push Button Switch #3 41
2.8 Initial Power Up 41
2.9 Display Contrast Adjustment 43
3.0 OPERATION 44
3.1 Stand-alone Mode 44
3.2 Network Mode 47
3.3 General Network Mode Protocol Information 49
3.4 Network Mode Timing Considerations 55
3.5 Command Protocol 60
3.6 LCD Display and Optional Back Light 82
3.7 Programming The STI 83
3.7.1 Programming Control Code and Mode Switch 84
3.7.2 Programming Alarm Set Points 86
3.7.3 Programming Custom Command Table 86
3.8 Error Codes 87
4.0 TROUBLESHOOTING AND MAINTENANCE 89
4.1 Cable Isolation and Connectivity Tests 91
4.2 Current Tests 91
4.3 Using Built-in Diagnostics 93
4.4 Replacing Printed Circuit Boards 95
4.5 Upgrading Firmware 96
APPENDIX A - References 97


1.0 INTRODUCTION
The Side Tank Indicator (STI) is part of the MTS Level Plus®product
line. It it offers a liquid crystal display (LCD) to indicate tank condi-
tions, an EIA-485 serial interface and a NEMA 4 type enclosure. The
LCD consists of sixteen seven-segment characters and thirty-one special
icons that indicate various tank conditions. The STI is compatible with
other MTS Level Plus digital EIA-485 devices including:
• Direct Digital Access (DDA) tank gauges
• Level Plus Tank Gauge Monitor
• Level Plus System80 (LPS80)
• HT-100 Hand Held Terminal
The STI has two modes of operation.
1. Network Mode: In this mode, the STI represents one slave device on
the multi-drop network controlled by a host device such as the Level
Plus Tank Gauge Monitor or LPS80.
2. Stand-Alone Mode: In this mode the STI assumes the role of host and
it is in control of the network. A single STI module can interrogate up
to eight DDA tank gauges and display level and temperature data
received from them.
The STI electronics include three printed circuit boards: the base board,
the microprocessor board, and the display board. The standard STI
housing is a NEMA 7 type enclosure. The cover has heat-treated glass,
wrenching lugs and a neoprene gasket seal. The base board mounts to
the bottom of the enclosure with four screws. The microprocessor and
display PCBs form an “electronics module” (hereafter referred to as the
module), which plugs into the base board mounted at the bottom of
the enclosure. No screws or spacers are required to attach the module
to the base board. The module is contained in a plastic shroud, and
can be easily be removed so that field wiring can be installed. Field
wiring is made to the P1 and P2 terminal blocks which are located on
the base board, under the module.
The STI display and the DDA gauge when combined with a Level Plus
Monitor (or with a PC that is running LPS80™ software) can be config-
ured for various applications. This manual covers only the STI display.
When necessary, you may need to consult manuals for the other
devices when designing your tank gauging system.
1

Other manuals:
• Level PlusTank GaugeMonitor Installationand OperationManual (P/N550421)
• DDA Tank Gauge Installation and Operation Manual (P/N 550164)
• Hand-Held Terminal (HT100) Operation Manual (P/N 550424)
• LPS80 Installation and Operation Manual (P/N 550429)
2

1.1 Specifications
Environmental:
Operating Temperature: Electronics: -40 to 176°F (-40 to 80°C)
LCD: 14 to 158°F (-10 to 70°C)
Storage Temperature -40 to 185°F
(-40 to 85°C)
Humidity: 0% to 100% R.H.*
Vibration: TBD
Shock: TBD
Mechanical:
Enclosure: NEMA 4 (outdoor)*
Mounting: Supported by rigid conduit or by cus-
tomer provided bracket
Entry Points: (2) - 3/4” NPT
Electrical:
Input Voltage: 24 to 26 Vdc
Sleep Mode Current: 1.5 mA maximum
Operating Current: 15 mA maximum
Back Light Current: 50 mA maximum (optional)
Display: Custom Liquid Crystal Display
Display Precision: ±0.01” (decimal mode)
±1/16” (fractional mode)
Display Contrast: User adjustable
Serial Interface: EIA-485
8 - Bit ASCII MTS Protocol
Communications:
Baud Rate: 4800
Parity: Even
Data Bits: 8
Stop Bits: 1
Safety Approvals (pending):
• Factory Mutual Research Corporation (FMRC) intrinsic safety approval
for Class I, II, III, Division 1, Groups C, D, E, F, and G hazardous areas.
• FMRC dust ignition-proof for Class II and III, Division 1, Groups E, F,
and G hazardous areas.
• FMRC approval for outdoor NEMA 4 locations*.
* With proper installation and conduit seals
3

2.0 INSTALLATION
STI installation has three phases: (1) mounting the enclosure,
(2) wiring, (3) and setup. Each phase of installation will be discussed in
detail. Guidelines will be presented for each phase. Before proceeding
with the installation, identify the mode that you want the STI to operate
in (i.e., Stand-alone or Network). If the STI is going to be operated in a
hazardous environment, the system must be installed according to MTS
drawing #650591. Special precautions are necessary when installing and
operating the STI in an intrinsically safe environment. Throughout this
manual, the appropriate instructions are dependent upon the mode of
operation selected. Special instructions or recommendations are given
when intrinsic safety is required. Pay special attention to the setup
phase. In the setup phase, the user must set switch configurations
defined by the mode of operation selected.
Figure 2.1 STI Enclosure Dimensions
lLEVEL PLUS
SIDE TANK INDICATOR
l
Prod. Type
Model No.
Serial No.
Mfg. Date
Side Tank Indicator
5.00 in.
(127 mm)
2.25 in.
(57.15 mm)
5.00 in.
(127 mm)
4.25 in dia.
(107.95 mm)
3.75 in.
(95.25 mm)
1.00 in. (25.4 mm)
3/4 NPT
(2 places)
CAUTION:
Always verify that the power is OFF
before installing or removing the
Microprocessor / Display “module”. Use
caution when handling this assembly.
Use static sensitive device handling pro-
cedures. Do not allow contaminants to
enter the assembly when it is removed
from the housing. Place the module in a
safe, clean environment until installed.
4

2.1 Mounting The Enclosure
Mount the STI on a flat, vertical surface. Choose a surface that
is free from obstructions that would make viewing the display
or removing the cover difficult. Also, take into account the
location of the sun or other light sources and how it might
affect the ability to view the LCD display clearly (without
glare). The STI enclosure should have plenty of clearance for
protective conduits. The STI base board can be removed and
rotated 90 degrees to allow the enclosure to be mounted in a
vertical or horizontal position. Conduits should also be sealed
and routed in a fashion to keep liquids from entering the
enclosure. See figure 2.2.
Figure 2.2 Mounting Orientation
lLEVEL PLUS
SIDE TANK INDICATOR
Seal unused entry
Cable Gland or
Chico Seal Here
Vertical mounting orientation
(thisviewshownwith electronicmodule removed)
One of four screws.
Remove all four screws
to rotate baseboard
Cable Gland or
Chico Seal Here
Horizontal mounting orientation
5

Before mounting, consult the National Electrical Code (NEC)
and local electrical codes as necessary in reference to mount-
ing NEMA 4 style enclosures. The enclosure is supported by
protective conduit on one or two sides (3/4” NPT fittings). If
the conduit is going to be connected on one side only, the
other entry point on the opposite side must have a protective
seal installed. Support the conduit as close as possible to the
enclosure. If conduits are going to connect to both sides of the
enclosure, then both conduits should be supported close to the
STI unit.
Remove the cover from the enclosure by rotating it counter
clockwise. Remove the electronics module from the enclosure
by putting your thumb and index finger on the outer groove of
the plastic shroud and pulling the module toward you. It is not
necessary to remove any of the screws from the front bezel to
remove the electronics module. Place the module in a safe
place where it will be protected from dirt and other contami-
nants. It is recommended that the module be placed into the
box that the STI was received in until it is needed. The base
board should remain mounted in the enclosure. See MTS draw-
ing 650597 in section 2.5 for wiring termination information.
Be careful when working with the enclosure to avoid damage
to the base board inside the enclosure. After the enclosure has
been mounted and the wiring completed, be sure to remove all
metal shavings and/or wire strands that may cause damage to
the STI electronics (use of a vacuum is recommended).
Reinstall the electronics module, then replace the enclosure
cover and tighten for proper seal.
CAUTION:
Chico seals or cable glands are recom-
mended to keep moisture that may be
present in the wiring conduits from
entering the STI enclosure.
6

2.2 Cable Requirements
The wiring connections for the DDA/STI system are based on
an EIA-485 multidrop network as shown in Figure 2.3A and
2.3B. A typical network consists of the main wire trunk and
individual tap connections to each STI display and DDA tank
gauge. The main trunk as well as each tap connection consists
of four wires that provide power and communications to each
device on the network. The DDA/STI network is approved as
an intrinsically safe system when used with the zener safety
barriers listed on MTS installation drawing #650591 (in this sec-
tion). The approvals cover Class I, II, III, Division 1, Groups C-
G hazardous locations.
Safety barriers are used to limit the amount of energy (current
x volts) available to devices on the EIA-485 network. The STI
can achieve low power operation in Network Mode by staying
in a sleep mode until a command is sent by the host device. In
sleep mode, each STI draws about 1.5mA. When activated by a
command (in Network Mode) or if operating in Stand-Alone
Mode, the STI has a maximum current draw of 15 mA (does
not include DDA tank gauge current). The network, including
the safety barriers must be able to support the required energy
to allow the DDA gauges and STI displays to work properly.
The resistance of the safety barrier combined with the resis-
tance of the cable then become the dominate factors in estab-
lishing the type and length of cables that can be used.
Figure 2.3A DDA/STI Network
(Network Mode)
STI
4
STI
4
STI
4
STI
4
4 4 4 4 4
4
Maximum tap length = 200 feet
Power
Supply 2
2
Computer
IntrinsicSafety
Barriers
7

Figure 2.3B DDA/STI Network
(Stand-alone mode)
The capacitance of the cable also affects the network operation
and must be considered when selecting cable for the network.
The primary consideration is that the capacitance of the cable is
an energy storage element and affects intrinsic safety aspects of
the network. The secondary consideration is that the capacitance
will attenuate the transmitted digital data. Since the communica-
tion baud rate is low (4800 baud), the voltage storage aspect of
the cable is the dominate factor in determining cable types and
lengths. In addition, each STI or DDA on the network represents
a fixed capacitance on the network that must be included in the
total capacitance of the network. The capacitance at the power
supply input terminals of each device is 1600 pF and the commu-
nication input terminals is 4000 pF. In all applications, the total
capacitance of the cables and the total capacitance of all the DDA
gauges and STIs on the network must be less than the allowable
capacitance (Ca) specified for the safety barriers.
The inductance of the cable similarly affects the intrinsic safety of
the network and must be considered when making a cable selec-
tion. The inductance of the cable is an energy storage element
and adversely affects the intrinsic safety of the network. The STI
has zero inductance associated with the power supply and com-
munications input terminals. In all applications, the inductance
associated with the cables must be less than the allowable induc-
tance (La) specified for the associated barriers.
All cable selections must meet the requirements as specified in
the installation drawing #650591 (in this section). The power sup-
ply cable must be 24 AWG (American Wire Gauge) or heavier,
shielded twisted pair with a capacitance of 50 picofarads per foot
or less. The communication cable must be 24 AWG or heavier
pair with a capacitance of 24 picofarads per foot or less.
2
Power
Supply 2IntrinsicSafety
Barrier
4
4
STI
44
8

9

10

11

Since the resistance of the cable is the dominant factor in
determining the maximum cable length of the network, heavier
gauge cables will allow longer cable runs. This is true because
heavier gauge cables have lower resistance ratings per foot.
For example, the resistance of a typical 22 AWG cable is 15
ohms per 1000 feet of cable where as 18 AWG cable is 6 ohms
per 1000 feet of cable. The power supply cable and the com-
munications cable selected should be same size (AWG). See
Section 2.3 in this manual for recommended cable types.
The barrier type also affects the maximum length of the cable.
This is because each barrier has a different series resistance. A
DDA/STI network that uses safety barriers with higher series
resistance will consequently have shorter maximum cable
lengths and will handle fewer devices on the network. Safety
barrier selection is determined by the power supply circuit
only. The resistance of the communications circuit safety barri-
er is not critical and does not need to be considered when
determining cable type or maximum cable runs.
The cable selection graphs are based on the resistance factors
of the DDA/STI network and do not account for capacitance
and inductance aspects. In many cases, maximum cable length
may be limited by the total capacitance or total inductance of
the network so that the intrinsic safety of the network is
maintained. As previously mentioned, the capacitance and
inductance of the network taps must be considered in the total
capacitance of the network.
In summary, to maintain the intrinsic safety of the DDA/STI
network:
For the power supply circuit (and optional backlight circuit):
Ca(barrier) > C(cable) + C(displays) + C(gauges)
1. C(gauge) or C(displays) = 1600 picofarads per device
2. La(barrier) > L(cable)
For the communications circuit:
Ca(barrier) > C(cable) + C(displays) + C(gauges)
1. C(gauge) or C(displays) = 4000 picofarads per device
2. La(barrier) > L(cable)
The cable selection graphs (figures 2.4, 2.5, and 2.6) indicate
possible cable lengths up to 8000 feet in certain applications.
Cable lengths of this maximum distance can only be achieved
12

if both the cable selection (for the communications circuit) and
the communications driver chip (from the host interface) meet
the requirements as defined by the EIA-485 standard. The EIA-
485 standard states that cable for the communications circuit
must have a nominal impedance of 120 ohms and be of the
low capacitance type (less than 20 picofarads per foot). In
addition, any communications driver chip on the network must
be able to drive 32 loads. The EIA-485 standard does not apply
to the cable selection for the power supply.
13

Figure 2.4 Cable Selection (using STAHL Safety Barriers)
5
10
15
20
0
Feet
Meters 1K
305 2K
610 3K
914 4K
1219 5K
1524 6K
1829 8K
2438
7K
2134
Cable Distance
(Maximum Permissible Cable Length = 8,000 ft.)
24 AWG
22 AWG
20 AWG
18 AWG
5
10
15
20
0
Cable Distance
(Maximum Permissible Cable Length = 8,000 ft.)
24 AWG
22 AWG
20AWG
18 AWG
Feet
Meters 1K
305 2K
610 3K
914 4K
1219 5K
1524 6K
1829 8K
2438
7K
2134
26 Volt Power Supply
w/STAHL Safety Barrier
8901/31-280/165/80
(Barrier Resistance = 201 ohms)
24 Volt Power Supply
w/STAHL Safety Barrier
8901/31-280/165/80
(Barrier Resistance = 201 ohms)
Number of STIs and DDAs on Network
Number of STIs and DDAs on Network
14

Figure 2.5 Cable Selection (using MTL Safety Barriers)
26 Volt Power Supply
w/MTL Safety Barrier MTL 728
(Barrier Resistance = 340 ohms)
24 Volt Power Supply
w/MTL Safety Barrier MTL 728
(Barrier Resistance = 340 ohms)
5
10
15
20
0
Cable Distance
(Maximum Permissible Cable Length = 8,000 ft.)
24 AWG
22 AWG
20 AWG
18 AWG
Feet
Meters 1K
305 2K
610 3K
914 4K
1219 5K
1524 6K
1829 8K
2438
7K
2134
Number of STIs and DDAs on Network
5
10
15
20
0
Cable Distance
(Maximum Permissible Cable Length = 8,000 ft.)
24 AWG
22 AWG
20 AWG
18 AWG
Feet
Meters 1K
305 2K
610 3K
914 4K
1219 5K
1524 6K
1829 8K
2438
7K
2134
Number of STIs and DDAs on Network
15

Figure 2.6 Cable Selection (using P&F Safety Barriers)
Number of STIs on Network
Number of STIs on Network
5
10
15
20
0
Cable Distance
(Maximum Permissible Cable Length = 8,000 ft.)
24 AWG
22 AWG
20AWG
18 AWG
Feet
Meters 1K
305 2K
610 3K
914 4K
1219 5K
1524 6K
1829 8K
2438
7K
2134
5
10
15
20
0
Cable Distance
(Maximum Permissible Cable Length = 8,000 ft.)
24 AWG
22 AWG
20AWG
18 AWG
Feet
Meters 1K
305 2K
610 3K
914 4K
1219 5K
1524 6K
1829 8K
2438
7K
2134
26 Volt Power Supply
w/P&F Safety Barrier Z428/Ex
(Barrier Resistance = 327 ohms)
24 Volt Power Supply
w/P&F Safety Barrier Z428/Ex
(Barrier Resistance = 327 ohms)
16
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