Geokon 8032 User manual

INSTRUCTION MANUAL
MODEL 8032
TERMINAL BOARD AND 16/32 CHANNEL MULTIPLEXER
No part of this instruction manual may be reproduced, by any means, without the written consent of
Geokon, Inc.
The information contained herein is believed to be accurate and reliable. However, Geokon, Inc. assumes
no responsibility for errors, omissions or misinterpretation. The information herein is subject to change
without notification.
Copyright © 2015 by Geokon, Inc.
(Doc Rev H, 6/1)

Warranty Statement
Geokon, Inc. warrants its products to be free of defects in materials and workmanship, under
normal use and service for a period of 13 months from date of purchase. If the unit should
malfunction, it must be returned to the factory for evaluation, freight prepaid. Upon examination
by Geokon, if the unit is found to be defective, it will be repaired or replaced at no charge.
However, the WARRANTY is VOID if the unit shows evidence of having been tampered with or
shows evidence of being damaged as a result of excessive corrosion or current, heat, moisture or
vibration, improper specification, misapplication, misuse or other operating conditions outside of
Geokon's control. Components which wear or which are damaged by misuse are not warranted.
This includes fuses and batteries.
Geokon manufactures scientific instruments whose misuse is potentially dangerous. The
instruments are intended to be installed and used only by qualified personnel. There are no
warranties except as stated herein. There are no other warranties, expressed or implied, including
but not limited to the implied warranties of merchantability and of fitness for a particular purpose.
Geokon, Inc. is not responsible for any damages or losses caused to other equipment, whether
direct, indirect, incidental, special or consequential which the purchaser may experience as a
result of the installation or use of the product. The buyer's sole remedy for any breach of this
agreement by Geokon, Inc. or any breach of any warranty by Geokon, Inc. shall not exceed the
purchase price paid by the purchaser to Geokon, Inc. for the unit or units, or equipment directly
affected by such breach. Under no circumstances will Geokon reimburse the claimant for loss
incurred in removing and/or reinstalling equipment.
Every precaution for accuracy has been taken in the preparation of manuals and/or software,
however, Geokon, Inc. neither assumes responsibility for any omissions or errors that may appear
nor assumes liability for any damages or losses that result from the use of the products in
accordance with the information contained in the manual or software.

TABLE of CONTENTS
1. THEORY OF OPERATION....................................................................................................................1
1.1 GK-403 MODE OF OPERATION ..............................................................................................................4
1.2 MICRO-800/MICRO-1000 MODE OF OPERATION ...............................................................................6
2. INSTALLATION AND WIRING............................................................................................................7
2.1 INSTALLATION.......................................................................................................................................7
2.2 WIRING..................................................................................................................................................7
2.3 DATALOGGER CONNECTION................................................................................................................10
3. MAINTENANCE ....................................................................................................................................10
4. TROUBLESHOOTING..........................................................................................................................11
APPENDIX A - SPECIFICATIONS .........................................................................................................12
APPENDIX B - CONNECTOR AND CABLE WIRING ........................................................................14
APPENDIX C - MANUAL SWITCH INSTRUCTIONS.........................................................................16
APPENDIX D –DAISYCHAIN OPERATION.......................................................................................17
APPENDIX E - MAXIMUM 8032-5 (TAN CABLE) CABLE LENGTHS............................................19
APPENDIX F –MEMS SENSOR TO MULTIPLEXER WIRING .......................................................20

LIST of FIGURES, TABLES and EQUATIONS
FIGURE 1-16 CHANNEL SWITCHING BLOCK DIAGRAM .................................................................................. 2
FIGURE 2-32 CHANNEL SWITCHING BLOCK DIAGRAM .................................................................................. 3
FIGURE 3-16 OR 32 CHANNEL SELECTION ..................................................................................................... 3
FIGURE 4–GK-403/DATALOGGER SELECTION.......................................................................................... 4
FIGURE 5-16 CHANNEL GK-403 CHANNEL SELECTION TIMING .................................................................... 4
FIGURE 6-32 CHANNEL GK-403 CHANNEL SELECTION TIMING .................................................................... 5
FIGURE 7-16 CHANNEL MICRO-800/MICRO-1000 CHANNEL SELECTION TIMING...................................... 6
FIGURE 8-32 CHANNEL MICRO-800/MICRO-1000 CHANNEL SELECTION TIMING...................................... 6
FIGURE 9-MULTIPLEXER ENCLOSURE MOUNTING DIMENSIONS.................................................................... 7
TABLE 1-16 CHANNEL MULTIPLEXER/TERMINAL BOARD WIRING................................................................ 8
TABLE 2-32 CHANNEL MULTIPLEXER/TERMINAL BOARD WIRING................................................................ 8
FIGURE 10-TERMINAL BOARD LAYOUT.......................................................................................................... 9
TABLE B.1 –J4 (I/O) CONNECTOR ................................................................................................................ 14
TABLE B.2 –P1 (I/O) CONNECTOR................................................................................................................ 14
TABLE B.3 –J1/J2 (TERMINAL BOARD)CONNECTORS.................................................................................. 15
FIGURE 11 -MANUAL SWITCH PANEL &ENCLOSURE................................................................................... 16
TABLE D.1 –DAISYCHAIN OPERATION/CHANNELS ACCESSED ..................................................................... 17
FIGURE D.1: DAISYCHAIN CONFIGURATION.................................................................................................. 18
FIGURE E.1: RECOMMENDED MAXIMUM CABLE LENGTH............................................................................. 19

1
1. THEORY OF OPERATION
The Model 8032 Terminal Board and Multiplexer expands the number of channels that
can be read by the MICRO-800 Datalogger, MICRO-1000 Datalogger or GK-403
Vibrating Wire Readout Box. Channel switching is accomplished by mechanical relays
mounted on the underside of the circuit board and the transducer connections are
accomplished by friction locking spring-loaded terminals mounted on the top side of the
circuit board.
There are two different varieties of 8032 board:
8032-E Terminal Board only –typically used in conjunction with a 4999 Manual
Switch Box
8032-C Terminal Board with Multiplexer –typically used with the Micro-800
Datalogger, MICRO-1000 Datalogger or GK-403 Readout Box.
Two switching configurations are supported, 16 channels of 4 conductors or 32 channels
of 2 conductors. For the 8032-C, these configurations are set by a DipSwitch on the top
side of the circuit board. A second DipSwitch selects whether the 8032-C is being used
with a datalogger or GK-403 Readout Box. For the 8032-E, these configurations are
determined by the 4999 Manual Switch Box.
To protect against lightning or EMI/RFI induced transients, each channel is protected by
an integrated lightning protection system, incorporating 230V tripolar plasma surge
arrestors, 150V bipolar plasma surge arrestors, 10uH inductors and 16V transient voltage
protection diodes. See Appendix A for complete specifications on these components.

2
Supported switching arrangements:
Relay
Control
Microcontroller
12V
GROUND
RESET
CLOCK
COM HI 1
COM LO 1
GK-403 or
CR800/CR1000
Sensor #1
12V
GROUND
RESET
CLOCK
Multiplexer/Terminal Board
AG
Sensor
Shield
COM HI 2
COM LO 2
Sensor #16
Sensor
Shield
1H
2H
1L
2L
S1
31H
32H
31L
32L
S16
Figure 1 - 16 Channel Switching Block Diagram
The 16 channel 4 wire switching configuration is typically used to multiplex 4 wire
sensors such as resistance strain gage load cells. It is also used to switch connections for
instruments which have more than one sensor integral to them, such as vibrating wire
pressure transducers with an integral thermistor for measuring temperature.

3
Relay
Control
Microcontroller
12V
GROUND
RESET
CLOCK
COM HI
COM LO
GK-403 or
CR800/CR1000
Sensor #1
Sensor #32
12V
GROUND
RESET
CLOCK
Multiplexer/Terminal Board
AG
Sensor
Shield
Sensor
Shield
1H
1L
S1
32H
32L
S16
Figure 2 - 32 Channel Switching Block Diagram
The 32 channel 2 wire switching configuration is typically used to multiplex 2 wire
sensors such as a vibrating wire pressure transducers, thermistors or thermocouples.
The multiplexer is powered by a nominal 12 VDC supply. Two control lines (RESET
and CLOCK) determine how channel selection is accomplished. Two schemes are
supported - one when connected to the GK-403 Vibrating Wire Readout Box and the
other when connected to MICRO-800 or MICRO-1000 dataloggers. See the following
sections explaining how each mode operates.
Figure 3 illustrates the DIP switch SW1 position 1 for switching between 16 and 32
channel operation. SW1 switch 1 ON = 32 channel, OFF = 16 channel. In Figure 3, 32
channel mode is chosen:
Figure 3 - 16 or 32 Channel Selection
ON
OFF
SW1
1
2
3
4

4
Figure 4 illustrates the DIP switch SW2 for switching between a GK-403 or Datalogger
application. “DATALOGGER”” is the default SW2 position:
Figure 4 –GK-403/DATALOGGER Selection
1.1 GK-403 Mode of Operation
The GK-403 mode of operation uses a single control line to select channels. This scheme
allows individual channels to be selected without having to sequentially advance through
all channels. Multiplexers can also be connected together in a daisy chain fashion using
the GK-403 protocol. In 16 channel mode, the number of clock pulses equals 2 times the
desired channel number. In 32 channel mode, the number of clock pulses equals the
desired channel number plus 1. Note the timing below for 16 and 32 channel switching
arrangements.
Clock
Channel 2
1
2
Timing:
T2 = min 20 usec
T3 = min 40 µsec (25kHz)
T1 = min 20 usec
Channel Selected
3
Channel 1
1
T4 = 500 µsec
2
T1
T2
T3
T4
4
Figure 5 - 16 Channel GK-403 Channel Selection Timing
GK-403
DATALOGGER
SW2

5
Clock
T1
T2
T3
Channel 2
1
2
Channel Selected
Channel 1
1
T4
2
3
Timing:
T2 = min 20 usec
T3 = min 40 µsec (25kHz)
T1 = min 20 usec
T4 = 500 µsec
Figure 6 - 32 Channel GK-403 Channel Selection Timing
The GK-403 channel selection scheme is not well suited to long cable lengths. The
maximum recommended distance between the GK-403 and multiplexer is 50 feet (15
meters).

6
1.2 MICRO-800/MICRO-1000 Mode of Operation
The MICRO-800 and MICRO-1000 (which respectively utilize a CR800 and CR1000
controller, manufactured by Campbell Scientific, Inc. of Logan, Utah) mode of operation
uses two control lines to operate the multiplexer. The RESET line enables the
multiplexer and activates the MICRO-800/MICRO-1000 mode of clocking. Pulses
received on the CLOCK line sequentially increment the channels while the RESET line is
held high. See the timing diagram below;
The CLOCK line sequentially advances the channels beginning with channel 1. Note the
timing diagrams below for 16 and 32 channel switching, respectively.
Reset
Clock
Channel 1
T1
T2
T3
No Channel
Selected
No Channel
Selected
Channel 16
Pulse 1
Pulse 2
Pulse 31
Timing:
T2 = 2 mSsec(min)
T3 = 2 mSsec(min)
T1 = 50 mSec(min.)
Selected
Selected
Pulse 32
Figure 7 - 16 Channel MICRO-800/MICRO-1000 Channel Selection Timing
Reset
Clock
Channel 1
Channel 2
T1
T2
T3
No Channel
Selected
No Channel
Selected
Channel 32
Pulse 1
Pulse 2
Pulse 32
Selected
Selected
Selected
Timing:
T2 = 2 mSec (min)
T3 = 2 mSec (min)
T1 = 50 mSec (min)
Figure 8 - 32 Channel MICRO-800/MICRO-1000 Channel Selection Timing

7
2. INSTALLATION AND WIRING
2.1 Installation
The multiplexer (or terminal board alone) is housed in a Nema 4/4X weatherproof
enclosure. However, it is recommended that additional measures be taken to ensure that
water or other contaminants are prevented from entering and subsequently disrupting
operation of the equipment. For example, in field environments, it could be installed
inside an equipment trailer or shed. The enclosure should be mounted in an upright
fashion, i.e. on a wall. The holes located in the tabs at the top and bottom of the
enclosure are used for mounting. Note Figure 9 for mounting dimensions.
Figure 9 - Multiplexer Enclosure Mounting Dimensions
An earth ground lug is installed on the bottom of the enclosure. Drive a copper stake into
the ground (or use an existing grounded metal structure) and attach a large gauge copper
wire (>12 AWG) from earth ground to the earth ground lug of the enclosure.
2.2 Wiring
The enclosure has cable entries for passing the instrument cables to the terminal board.
These entries have seals for specific cable sizes which will minimize the possibility of
water or other contaminants entering the box and causing problems. Plastic dowels are
provided for unused cable entries to prevent moisture and contaminants from entering the
enclosure.
If the unit is equipped with manual switching the switch panel must be removed to access
the terminal board. See Appendix C for additional information.

8
Actual gage connections to the terminal board will vary depending on the instrument type
and cable used. Note the following tables to get the general idea.
Terminal
Board
Vibrating Wire
with Thermistor
Resistance Strain
Gage Bridge
Linear Potentiometer
(with Remote Sense)
1H
VW Sensor #1
S+ from Bridge #1
Excitation Pot #1
1L
VW Sensor #1
S- from Bridge #1
Wiper Output Pot #1
2H
Thermistor #1
P+ to Bridge #1
Remote Sense Pot #1
2L
Thermistor #1
P- to Bridge #1
Ground Pot #1
S1
Shield Drain Wire
from Sensor #1
Shield Drain Wire
from Bridge #1
Shield Drain Wire
from Pot #1
3H
VW Sensor #2
S+ from Bridge #2
Excitation Pot #2
3L
VW Sensor #2
S- from Bridge #2
Wiper Output Pot #2
4H
Thermistor #2
P+ to Bridge #2
Remote Sense Pot #2
4L
Thermistor #2
P- to Bridge #2
Ground Pot #2
S2
Shield Drain Wire
from Sensor #2
Shield Drain Wire
from Bridge #2
Shield Drain Wire
from Pot #2












31H
VW Sensor #16
S+ from Bridge #16
Excitation Pot #16
31L
VW Sensor #16
S- from Bridge #16
Wiper Output Pot #16
32H
Thermistor #16
P+ to Bridge #16
Remote Sense Pot #16
32L
Thermistor #16
P- to Bridge #16
Ground Pot #16
S16
Shield Drain Wire
from Sensor #16
Shield Drain Wire
from Bridge #16
Shield Drain Wire
from Pot #16
Table 1 - 16 Channel Multiplexer/Terminal Board Wiring
Terminal
Board
Vibrating Wire
Thermistor
Thermocouple
1H
VW Sensor #1
Thermistor #1
Thermocouple #1
1L
VW Sensor #1
Thermistor #1
Thermocouple #1
2H
VW Sensor #2
Thermistor #2
Thermocouple #2
2L
VW Sensor #2
Thermistor #2
Thermocouple #2
S1
Shield Drain Wires
from Sensors 1&2
Shield Drain Wires
from Thermistors 1&2
3H
VW Sensor #3
Thermistor #3
Thermocouple #3
3L
VW Sensor #3
Thermistor #3
Thermocouple #3
4H
VW Sensor #4
Thermistor #4
Thermocouple #4
4L
VW Sensor #4
Thermistor #4
Thermocouple #4
S2
Shield Drain Wires
from Sensors 3&4
Shield Drain Wires
from Thermistors 3&4












31H
VW Sensor #31
Thermistor #31
Thermocouple #31
31L
VW Sensor #31
Thermistor #31
Thermocouple #31
32H
VW Sensor #32
Thermistor #32
Thermocouple #32
32L
VW Sensor #32
Thermistor #32
Thermocouple #32
S16
Shield Drain Wires
from Sensors 31&32
Shield Drain Wires
from Thermistors 31&32
Table 2 - 32 Channel Multiplexer/Terminal Board Wiring

9
Figure 10 depicts the terminal board to which gage connections are made. If the terminal
board is equipped with manual switches, connectors J1 and J2 will have ribbon cables
that are connected to the switch boards.
Terminal Blocks T1/2 to T31/32 are for the gage connections.
Figure 10- Terminal Board Layout
J1
J2
1H
1L
2H
2L
S1
3H
3L
4H
4L
S2
5H
5L
6H
6L
S3
7H
7L
8H
8L
S4
9H
9L
10H
10L
S5
11H
11L
12H
12L
S6
13H
13L
14H
14L
S7
15H
15L
16H
16L
S8
17H
17L
18H
18L
S9
19H
19L
20H
20L
S10
21H
21L
22H
22L
S11
23H
23L
24H
24L
S12
25H
25L
26H
26L
S13
27H
27L
28H
28L
S14
29H
29L
30H
30L
S15
31H
31L
32H
32L
S16
J 4
EARTH
J4
T1/2
T3/4
T5/6
T7/8
T9/10
T11/12
T13/14
T15/16
T17/18
T19/20
T21/22
T23/24
T25/26
T27/28
T29/30
T31/32
SHLD
SHLD
C1H
C1L
C2H
C2L
SHLD
+12V
GND
RESET
CLOCK
SHLD
P1
GK-403
DATALOGGER
SW2
P1
SW1
P1
ON
OFF

10
2.3 Datalogger Connection
Following sensor and installation, connections between a Datalogger and Multiplexer(s) can be
made using the model 8032-5 interconnect cable. Each Multiplexer employed is connected to
the appropriate weather tight 10-pin Bendix connector mounted on the enclosure. Each
connector on a standard Datalogger is pre-wired to control and read the external Multiplexers.
3. MAINTENANCE
Maintenance for the Model 8032 Multiplexer/Terminal Board is minimal. The following
checks should be performed periodically though;

Is there water or other contaminants intruding into the enclosure? At times water can
wick through the sensor cables onto the terminal board. This will at some point cause
problems with the system. Water or other contaminants can also enter through
improper use of the cable entries. Additional sealing of the entries can be done with
various sealing compounds such as RTV. If moisture is condensing inside desiccant
can be used to keep this to a minimum. Desiccant is available from the factory.

Are connections corroding? If the unit is installed near salt water for example, salts
may form on the terminals inside the enclosure and cause malfunctions. In this event
check that the enclosure is properly sealed. Use sealing compounds if necessary.
Desiccant may also help prevent this buildup. Sealing sprays such as HumiSeal may
also help protect the connections.

Is the earth ground connection acceptable? Check that corrosion has not built up
around the connection to the enclosure (outside or in). Disassemble, sand the
connection location to remove rust or corrosion, and reattach if necessary.

11
4. TROUBLESHOOTING
Below are some commonly experienced problems along with possible remedial action.
Contact the factory if any problem remains unresolved or additional help is required.
A particular channel on the multiplexer appears to be malfunctioning.

Check sensor connections on the terminal board. Clean if corrosion exists.

Try moving the sensor wired to the suspect channel to another channel to verify the
malfunctioning of the channel (as opposed to the sensor).
No channels are working.

Inspect circuit board for shorts, opens, or other damage.

Is moisture present on circuit board? If so, install desiccant to absorb.
Channel selection appears to be random.

Has corrosion built up on the circuit board? Clean if necessary.

Is there a source of electrical noise nearby? Move multiplexer or noise source if
possible.

12
APPENDIX A - SPECIFICATIONS
A.1 General
Power Requirements: 10-16 VDC (unregulated)
Quiescent Current (MICRO-800/MICRO-1000 mode): 80

A (16CH mode)
130A (32CH mode)
Quiescent Current (GK-403 mode): 12 mA
Channel Activated Current: 30 mA
Control Line Input Impedance: 100 k

(CLOCK), 100 k(RESET)
Control Line Input Levels: TTL or RS-232 (

9 VDC)
Transient Protection: 16 VDC Transzorbs
Operating Temperature:

40 to

60

C
A.2 Relays
Type: NAIS TXS2SA-4.5V DPDT non-latching
Power: 11.1 mA @ 5VDC (55.5 mW)
Contact Type: Gold clad silver alloy
On Resistance: 100 m

Coil Resistance: 405

Maximum Switching Power: 30W (resistive)
Maximum Switching Voltage: 110 VDC
Maximum Switching Current: 1 A
Operate Time:

5 msec Max.
Release Time:

5 msec
Switching Life: 5 x 107operations (mechanical)
2 x 105operations (electrical @ 30W)
Ambient Temperature:

40 to +70

C
A.3 Tripolar Plasma Surge Arrestor
Nominal DC Breakdown Voltage: 230V
Surge Life: 100 (10/1000 ms pulse @ 200 A)
Maximum Surge Current: 5 kA per side (8/20

s pulse)
Insulation Resistance: 109

Operating Temperature:

65 to +125

C
A.4 Bipolar Plasma Surge Arrestor
Nominal DC Breakdown Voltage: 150V
Maximum Surge Current: 1 kA (8/20

s pulse)
Insulation Resistance: 1010

Operating Temperature:

65 to +125

C

13
A.5 Inductor
Rated Current: 4A
Inductance: 10µH (±20%)
D.C.R.: 25mMAX (at 20°C)
A.6 Transient Voltage Suppressor (Transorb)
Rated Power: 1500W
Peak forward Surge Current: 200A
Reverse Standoff Voltage: 16.0V
A.7 Transducer Connection Maximum Operating Voltage Levels:
Common-mode Voltage/Earth Ground: 16V(max)
Differential-mode Voltage (Channel # ‘H’ – Channel # ‘L’): 16V(max)
A.8 Reset and Clock Maximum Operating Voltage Levels:
Single-ended Control Voltage/System Ground: 16V(max)

14
APPENDIX B - CONNECTOR AND CABLE WIRING
J4
Inside
Color
10 Pin
Bendix
Description
8032-5 (TAN) Cable
Wire Color
1
Brown
A
COM HI 1
White
2
Red
B
COM LO 1
White's Black
3
Orange
C
COM HI 2 (16 channel)
Red
4
Yellow
D
COM LO 2 (16 channel)
Red's Black
5
Green
K
Analog Ground
Shield Drain Wires –all pairs plus overall
6
Blue
F
+12 Volt Power
Yellow
7
Purple
G
Power Ground
Yellow's Black
8
Grey
H
RESET (DATALOGGER)
SENSE (GK-403)
Green
9
White
J
CLOCK
Green's Black
10
E
No Connection
Blue & Blue’s Black (unused)
Table B.1 –J4 (I/O) Connector
P1 Terminal
Label
Description
8032-5 (TAN) Cable
Wire Color
1,2
SHLD
SHIELD
Shield Drain Wires –all pairs plus overall
3,4
SHLD
SHIELD
Shield Drain Wires –all pairs plus overall
5,6
C1H
COM HI 1
White
7,8
C1L
COM LO 1
White's Black
9,10
C2H
COM HI 2 (16 channel)
Red
11,12
C2L
COM LO 2 (16 channel)
Red's Black
13,14
SHLD
SHIELD
Shield Drain Wires –all pairs plus overall
15,16
+12V
+12 Volt Power
Yellow
17,18
GND
Power Ground
Yellow's Black
19,20
RESET
RESET
Green
21,22
CLOCK
CLOCK
Green's Black
23,24
SHLD
SHIELD
Shield Drain Wires –all pairs plus overall
-
-
No Connection
Blue & Blue’s Black (unused)
Table B.2 –P1 (I/O) Connector
Note: P1 is a “stacking” type connector. Odd number terminals are read left to right on the bottom
row. Even numbered terminals are read left to right on the top row.