Weidmuller WI-I-O 9-K User Manual

WI-I/O 9-K Wireless I/O

User Manual

For WI-I/O 9-1,2,3,4, products, refer to separate User Manuals

Weidmuller, Inc., Richmond, VA 23236

Tel: [phone] Fax: [phone]

Web: www.weidmuller.com

WI-I/O 9-K v1.9

Thank you for your selection of the WI-I/O 9-K product. We trust it will give you

many years of valuable service.

ATTENTION!

Incorrect termination of supply wires may

cause internal damage and will void warranty.

To ensure this product enjoys a long life,

double check ALL your connections with

the user’s manual

before turning the power on.

CAUTION:

This device should not be operated within 8 inches (20cm) of people, in accordance with
CFR 47 Section 1.1307

DO NOT:

• operate the transmitter when someone is within 20 cm of the antenna

• operate the transmitter unless all RF connectors are secure and any open connectors are

properly terminated.

• operate the equipment near electrical blasting caps or in an explosive atmosphere

All equipment must be properly grounded for safe operations. All equipment should be serviced
only by a qualified technician.

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User Manual v1.9

FCC Notice: WI-I/O 9-K Wireless Module

This Users Manual is for the WI-I/O 9-K wireless module. This device complies with Part 15.247
of the FCC Rules.

Operation is subject to the following two conditions:

1) This device may not cause harmful interference and

2) This device must accept any interference received, including interference that may cause
undesired operation.

This device must be operated as supplied by Weidmuller, Inc. Any changes or modifications
made to the device without the written consent of Weidmuller, Inc. may void the user’s authority
to operate the device.

This device MUST be installed by Professional Radio and Antenna personnel. Standard antenna
cables, and antennas must be used, these are available from vendors specified by Weidmuller,
Inc. Please contact Weidmuller, Inc. for end user antenna and cable recommendations.

Notices: Safety

Exposure to RF energy is an important safety consideration. The FCC has adopted a safety
standard for human exposure to radio frequency electromagnetic energy emitted by FCC
regulated equipment as a result of its actions in Docket 93-62 and OET Bulletin 65 Edition 97-

01.

Manual WI-I/O 9-K v1.9 Page 3

WI-I/O 9-K v1.9

Important Notice

Weidmuller, Inc. products are designed to be used in industrial environments, by experienced
industrial engineering personnel with adequate knowledge of safety design considerations.
Weidmuller, Inc. radio products are used on unprotected license-free radio bands with radio noise
and interference. The products are designed to operate in the presence of noise and interference,
however in an extreme case, radio noise and interference could cause product operation delays or
operation failure. Like all industrial electronic products, Weidmuller, Inc. products can fail in a
variety of modes due to misuse, age, or malfunction. We recommend that users and designers
design systems using design techniques intended to prevent personal injury or damage during
product operation, and provide failure tolerant systems to prevent personal injury or damage in
the event of product failure. Designers must warn users of the equipment or systems if adequate
protection against failure has not been included in the system design. Designers must include
this Important Notice in operating procedures and system manuals.
These products should not be used in non-industrial applications, or life-support systems, without
consulting Weidmuller, Inc. first.

1. For WI-I/O 9-x modules, a radio licence is not required in many countries, provided the
module is installed using the antenna and equipment configuration complying with the
country’s regulations.. Check with your local distributor for further information on
regulations.

2. For WI-I/O 9-x modules, operation is authorised by the radio frequency regulatory
authority in your country on a non-protection basis. Although all care is taken in the
design of these units, there is no responsibility taken for sources of external interference.
The WI-I/O 9-x intelligent communications protocol aims to correct communication
errors due to interference and to retransmit the required output conditions regularly.
However some delay in the operation of outputs may occur during periods of interference.
Systems should be designed to be tolerant of these delays.

3. To avoid the risk of electrocution, the antenna, antenna cable, serial cables and all
terminals of the WI-I/O 9-x module should be electrically protected. To provide
maximum surge and lightning protection, the module should be connected to a suitable
earth and the antenna, antenna cable, serial cables and the module should be installed as
recommended in the Installation Guide.

4. To avoid accidents during maintenance or adjustment of remotely controlled equipment,
all equipment should be first disconnected from the WI-I/O 9-x module during these
adjustments. Equipment should carry clear markings to indicate remote or automatic
operation. E.g. "This equipment is remotely controlled and may start without warning.
Isolate at the switchboard before attempting adjustments."

5. The WI-I/O 9-x module is not suitable for use in explosive environments without
additional protection.

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User Manual v1.9

Limited Warranty, Disclaimer and Limitation of Remedies

Weidmuller, Inc. products are warranted to be free from manufacturing defects for the
“serviceable lifetime” of the product. The “serviceable lifetime” is limited to the availability of
electronic components. If the serviceable life is reached in less than three years following the
original purchase from Weidmuller, Inc., Weidmuller, Inc. will replace the product with an
equivalent product if an equivalent product is available.

This warranty does not extend to:

- failures caused by the operation of the equipment outside the particular product's

specification, or

- use of the module not in accordance with this User Manual, or

- abuse, misuse, neglect or damage by external causes, or

- repairs, alterations, or modifications undertaken other than by an authorised Service Agent.

Weidmuller, Inc.’s liability under this warranty is limited to the replacement or repair of the
product. This warranty is in lieu of and exclusive of all other warranties. This warranty does not
indemnify the purchaser of products for any consequential claim for damages or loss of
operations or profits and Weidmuller, Inc. is not liable for any consequential damages or loss of
operations or profits resulting from the use of these products. Weidmuller, Inc. is not liable for
damages, losses, costs, injury or harm incurred as a consequence of any representations, warranties
or conditions made by Weidmuller, Inc. or its representatives or by any other party, except as
expressed solely in this document.

Manual WI-I/O 9-K v1.9 Page 5

WI-I/O 9-K v1.9

WI-I/O 9-K Radio Telemetry Module

USER MANUAL

1 OVERVIEW ----------------------------------------------------------------------------------------- 8

1.1 Input Signals.................................................................................................................8

1.2 Power Supply................................................................................................................9

1.3 Radio Transmitter.........................................................................................................9

1.4 Configuration..............................................................................................................10

2 OPERATION ---------------------------------------------------------------------------------------11

2.1 Normal Operation.......................................................................................................11

2.2 What information is transmitted over the radio?........................................................11

2.3 How often is the input information sent by radio?.....................................................11

2.4 Inputs ..........................................................................................................................12

2.4.1 Digital Inputs................................................................................................................... 12

2.4.2 Pulse Inputs..................................................................................................................... 12

2.4.3 Shaft Encoder Inputs....................................................................................................... 14

2.4.4 Pulse Rates ...................................................................................................................... 14

2.4.5 Analog Inputs.................................................................................................................. 15

2.4.6 Setpoint Status ................................................................................................................ 17

2.4.7 Supply Voltage................................................................................................................ 17

2.4.8 Low Supply Voltage Alarm (Supply LowVolts) ............................................................ 17

2.4.9 Supply Failure................................................................................................................. 17

2.4.10 Communications Failure................................................................................................. 17

2.5 How to Design a Remote Monitoring System............................................................18

2.5.1 Achieving reliable radio transmission ............................................................................ 18

2.5.2 How far will the radio transmit? .....................................................................................19

2.6 Calculating Power Consumption................................................................................20

2.7 Security Considerations..............................................................................................22

3 HARDWARE INSTALLATION ---------------------------------------------------------------23

3.1 How to mount the WI-I/O 9-K ...................................................................................23

3.2 Antenna Installation....................................................................................................24

3.2.1 Dipole and Collinear antennas. ....................................................................................... 26

3.2.2 Yagi antenna. ..................................................................................................................26

3.3 Connection Plug .........................................................................................................27

3.3.1 PL1-K Plug Lead.............................................................................................................28

3.4 Power Supply Installation...........................................................................................28

3.4.1 External Power................................................................................................................ 28

3.4.2 Battery Pack WI-BP-I/O-9-K.......................................................................................... 29

3.4.3 External Battery Supplies ............................................................................................... 30

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User Manual v1.9

3.5 Input Signal Connections............................................................................................31

3.5.1 Digital/Pulse Inputs......................................................................................................... 31

3.5.2 Shaft Encoder Connections............................................................................................. 31

3.5.3 Analog Input....................................................................................................................31

3.5.4 RS232 serial port............................................................................................................. 33

4 CONFIGURATION-------------------------------------------------------------------------------34

4.1 I/O Mapping................................................................................................................35

4.2 Update Transmission Times.......................................................................................36

4.3 Digital Inputs..............................................................................................................36

4.4 Analog Input...............................................................................................................37

4.5 Analog Setpoints.........................................................................................................38

4.6 Supply Voltage ...........................................................................................................39

4.7 Pulse Inputs.................................................................................................................40

4.7.1 Manually Setting Counter Values................................................................................... 43

4.7.2 Shaft Encoder Inputs....................................................................................................... 43

4.7.3 Pulse Rates ...................................................................................................................... 43

4.8 Number of Transmissions...........................................................................................44

4.9 Programming Configurations to Modules..................................................................44

4.10 Loading Configuration from a Module.......................................................................45

4.11 Print Options...............................................................................................................45

5 DIAGNOSTICS AND TESTING---------------------------------------------------------------46

5.1 System Problems ........................................................................................................46

5.2 LED Indicators............................................................................................................46

5.3 Diagnostic Features ....................................................................................................46

5.3.1 Read Inputs......................................................................................................................47

5.3.2 Setting Counter Values ...................................................................................................48

5.3.3 Calibrating Analog Input.................................................................................................48

5.3.4 Tone Reversals................................................................................................................ 49

5.3.5 Firmware Version ...........................................................................................................49

6 SPECIFICATIONS--------------------------------------------------------------------------------50

7 WARRANTY ---------------------------------------------------------------------------------------53

Manual WI-I/O 9-K v1.9 Page 7

WI-I/O 9-K v1.9

1 OVERVIEW

Note: Please refer to separate User Manuals for the WI-I/O 9-1,2,3,4 products.

The WI-I/O 9-K product will be referred to as the “WI-I/O K” for the rest of this manual to
clearly delineate it from the other WI-I/O 9-1,2,3,4 products.

The WI-I/O K radio telemetry module is an economical solution for the remote monitoring of
process signals. The WI-I/O K can connect to digital, pulse or analog signals from process
transducers, and transmit these signal values by radio.

Although the WI-I/O K is intended to be simple in its application, it also provides many
sophisticated features. This manual should be read carefully to ensure that the modules are
configured and installed to give reliable performance. The WI-I/O K has been designed to use a
European licence-free radio band at 869MHz. The WI-I/O K uses the 869MHz WI-I/O 9-x
module as a receiver, or repeater. If you have not used WI-I/O 9-x modules before, please read
the WI-I/O 9-x User Manual prior to reading this manual.

The WI-I/O K module is a monitoring only unit - that is, it will only accept input signals and
does not provide output signals. The WI-I/O K has an internal radio transmitter; it does not have
a receiver to receive messages from another module.

The WI-I/O K transmits the value of an input signal whenever the signal changes, and also after a
pre-configured time. Each transmission message includes error-checking to confirm the validity
of the message. At each transmission, the WI-I/O K may be configured to repeat the
transmission several times to ensure that the transmission is received correctly. This is important
if the radio path is marginal (that is, the radio signal is not strong) or if there is a lot of radio
traffic on the radio channel which may corrupt the WI-I/O K message. The WI-I/O K transmits
the input message to a WI-I/O 9-x module, which sets an output signal to be the same value as
the WI-I/O K input, or the WI-I/O 9-x passes the input message to another device (PC or PLC)
via its serial port.

For more information on the WI-I/O 9-x module, please refer to the WI-I/O 9-x User Manual.

The WI-I/O K has a heavy duty painted aluminium enclosure, weather-proofed to NEMA 4 /
IP66, except in Class 1 Div 2 areas. Signal and power connections to the unit are made via a
weatherproof connector at the bottom of the module. Antenna connection is made using a SMA
coaxial connector at the top of the module. Signal and antenna connections should be wrapped
with waterproofing tape to ensure weatherproof integrity.

In North America, the WI-I/O K is approved for use in Class 1 Division 2 areas.

1.1 Input Signals

The WI-I/O K module provides two digital/pulse inputs and one analog input for connecting to
process transducers.

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User Manual v1.9

Digital Signals

Examples: motor fault, tank overflow, intruder alarm

Pulse signals - use the same input as the digital input

Examples: electricity metering, fluid flow, rain gauge, level from a shaft encoder

Analog continuously variable signals (0-20mA, 4-20mA, 0-10mA, 0-10V)

Examples: measured tank level, measured process temperature

Some internal signals may also be transmitted to outputs in the network:

• Setpoint Status (digital signal set or reset depending upon the value of the analog signal

compared to a high and a low setpoint value configured in the WI-I/O K)

• Supply Low Voltage (digital signal set when supply voltage is low).

• Supply Voltage (analog value)

• Pulse Rate (analog value proportional to rate of pulse input - available for both pulse inputs)

1.2 Power Supply

The power consumption of the WI-I/O K is very small as it conserves power by reverting to
“sleep” mode between transmissions. The WI-I/O K can be powered from a 6 - 30 VDC supply.
An optional 9VDC battery pack, the WI-BP-I/O-9-K is available to power the WI-I/O K. The
battery supply uses six AA alkaline batteries. More than one WI-BP-I/O-9-K battery pack can be
connected together to supply a WI-I/O K. Other battery supplies can also be used to power the
WI-I/O K, including a solar panel supply.

The WI-I/O K unit provides an internal alarm on low supply voltage - this alarm may be
transmitted by radio for warning purposes. The user can configure the voltage at which the low
voltage alarm activates.

The WI-I/O K generates a 24VDC, 50mA supply for powering the analog loop. This supply is
designed to power an analog loop only and should not be used for any other purpose.

1.3 Radio Transmitter

The WI-I/O K has an internal frequency hopping radio transmitter that operates on a unlicensed
radio channel at 900 MHz. A radio licence is not required for the WI-I/O K in USA, Canada,
Australia, New Zealand and some other countries.

It is suitable for use in utility industries such as electricity, water and gas, as well as a cost
effective solution for short range applications in factories and industrial plants.

To extend radio range, WI-I/O 9-x modules can be used as repeaters. Up to five repeaters can

Manual WI-I/O 9-K v1.9 Page 9

WI-I/O 9-K v1.9

be configured for each input-to-output link. The configuration is done at the WI-I/O K module
where the input signal is - no additional configuration is required at the WI-I/O 9-x modules.
The transmitted radio message will include the address of repeater modules - modules with these
addresses will re-transmit the messages.

1.4 Configuration

Each module must be configured before it can be used. Configuration is performed using a PC
(or a laptop computer) connected to the module via the internal RS232 port on the WI-I/O K.
WI-I/O K configuration software is required and is provided with each order.

Configuring a module requires the entering of “input mappings” and setting operating parameters
for each input. An “input mapping” links an input signal to an output channel at a remote
module (or a “destination address”). An input mapping is entered for each input signal (external
and internal) which is used. Mappings may be inverted such that the output is the reverse value
of the input.

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User Manual v1.9

2 OPERATION

2.1 Normal Operation

Once configured using the WI-I/O K configuration software, the WI-I/O K module will normally
be in “sleep” mode to conserve power. During sleep mode, the microprocessor controller powers
down, and the analog loop supply is turned off. The microprocessor will automatically “wake
up” and revert to full operation if a digital/pulse input changes (on to off, or off to on), or every

0.5 seconds to check if a timed update transmission is due to be sent.

Normal operation of the WI-I/O K is indicated by a brief flicker of the OK LED light on the front
panel approximately every 10 seconds.

2.2 What information is transmitted over the radio?

The WI-I/O K modules transmit the value of the input signal in a data frame. The data frame
includes a system address, and the "address" of the transmitting (or “source”) WI-I/O K module
and the receiving (or “destination”) WI-I/O 9-x module, so that each transmitted message is acted
on only by the correct receiving unit. The system address is a common address used by all
modules in the same system. This allows multiple systems to operate within the same radio
range without "cross-talk" between systems.

The user configures these addresses as part of the module configuration. Each transmitted
message also includes error checking to ensure that no corruption of the data frame has occurred
due to noise or interference. If repeater modules are being used, then the addresses of these
intermediate modules are also included in the data frame.

The user can configure the WI-I/O K to transmit each message from one to five times to ensure
that at least one of the messages is received correctly. Each repeat transmission will occur at
random intervals between 0.5 and 2 seconds.

2.3 How often is the input information sent by radio?

• Change messages. The WI-I/O K transmits the value of an input signal whenever the signal

changes.

• Update messages. The input value is also transmitted if the signal has not changed within a

pre-configured update time (configurable 10 seconds to 7 days).

• Paralysis. When a WI-I/O K transmits a message for a particular input, the WI-I/O K will not

transmit another message for this input within a configured time period. This time is called
the paralysis time, and may be used to prevent a lot of messages being transmitted if an input
changes frequently. The paralysis time may be set from zero to 127.5 seconds for each input.
For example, assume the paralysis time on an input is 30 seconds. If the input changes, then
the WI-I/O K will transmit a message, however it will not transmit another message for this

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WI-I/O 9-K v1.9

input during the next 30 seconds, regardless of changes to the input signal. Note that
paralysis time does not stop re-transmissions of each message - if the WI-I/O K is configured
to transmit each message three times, then paralysis will not stop this.

Depending on the type of input signal (digital, pulse or analog), the WI-I/O K must determine
what type of signal change is required to send a transmission:

2.4 Inputs

2.4.1 Digital Inputs

A digital input can be an external digital input or an internal status input (setpoint status or low
voltage alarm). The WI-I/O K will accept digital inputs as voltage-free contacts, NPN devices
(such as proximity switches) or TTL signals. For TTL signals, a 0-1.5V signal will be measured
as on/active/1, and a 3.5-13V signal will be measured as off/inactive/0.

The WI-I/O K will transmit the value of the digital input whenever it changes from off to on or
from on to off. A paralysis time may be configured to prevent another transmission within this
time. The WI-I/O K will also transmit an update message if a message has not been transmitted
for that input within an “update time”.

There are two update times for each digital input - one for when the input is on, and one for when
the input is off. Each update time may be configured between 10 seconds and 5 days. For
example, a digital input may be configured to update every 1 day when the input is off, but
update every 10 minutes when the input is on. If an update time of zero (or less than 10 seconds)
is selected, then no update messages will be sent.

Overview:

• Input value transmitted on input change

• Update message if the input value has not been transmitted within the configured update time

for that input (10 seconds - 7 days)

• Separate update times for on and off status for digital inputs

• After each transmission, further transmission for that input is disabled for the paralysis time (0

– 127.5 sec).

The time response of the two digital inputs is different. DI1 has a fast response, sensing a change
within 10msec. This means that the overall “input-to-output’ response is approx 50 msec. DI2 is
checked every 500msec - the maximum response time of this input could be 550 msec.

2.4.2 Pulse Inputs

Pulse inputs use the same input connection as the digital inputs. The total number of digital and
pulse inputs available is two.

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User Manual v1.9

Each pulse input is counted as two 16 bit registers. The first register is the pulse count, and the
second register is the count of “overflows” of the first register - these two registers provide a 32
bit count of the pulse input. Each register can be transmitted individually. A “sensitivity” value
is configured for each pulse input (0 - 32 000). Whenever the pulse count has increased by this
value since the last transmission, the WI-I/O K will transmit the new pulse count. In addition, an
update transmission of the pulse count will be transmitted if the pulse count has not been
transmitted for the update time. If an update time of zero is selected, then no update messages
will be sent.

The maximum pulse input is:

 300Hz for contact or NPN inputs (1 msec minimum on-time and off-time), or

 10KHz (30 µsec minimum on-time and off-time) for TTL inputs. Up to 50KHz can be

achieved on PI2 provided the divider is set such that the scaled count rate is less than 10KHz
(see below).

There is no minimum pulse rate. For PI2, there is a configurable scaling divider (integer 1 –

255). This allows the pulse count to be scaled. If a divider of X is configured, then the pulse

count will increase by 1 for each X input pulses. There is a separate divider for each pulse input.
The divider parameter could be used for the following reasons:

 If the pulse count is to be transmitted to a pulse output on a WI-I/O 9-x, then the maximum

pulse rate is 100Hz. If the input rate is more than 100Hz, then it can be reduced with the
divider. For example, if the maximum input rate is 300Hz, then the use of a 10 divider will
bring the effective rate down to 30Hz - each output pulse will then represent 10 input pulses.

 The divider can be used to scale the pulse count to engineering units. For example, if the

input pulse rate is 7 pulses per m3 of gas, then a divider of 7 will result in a pulse count
corresponding to the number of m3. Note that the divider must be an integer.

 The divider could be used to slow down the pulse rate. If the input pulse rate is 5KHz, then

the base 16 bit counter will overflow in approx 13 seconds. If the overflow counter is not
used, then this may be too fast to be processed by HMI software. If a divider of 100 is used,
then the counter will take over 20 minutes to overflow.

There is no divider for PI1.

If the pulse count is transmitted to a pulse output on a WI-I/O 9-x module, the WI-I/O 9-x will
compare the input count to its own output count (the count of output pulses), and will then
output pulses until the two counts are the same. If the pulse counts are transmitted to a WI-I/O 9­C or WI-I/O 9-G interface module, then the WI-I/O 9-C/G will store the pulse count value in an
internal register.

For pulse rates higher than 10 Hz, the “Fast Pulsed Inputs” option should be selected. This
increases power consumption of the module significantly and this needs to be considered if using
a battery power supply.

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Overview:

• Pulse inputs are counted as 2 x 16 bit registers.

• Pulse count is transmitted when the count has increased by the sensitivity amount since the

last transmission.

• Update message if the input value has not been transmitted within the update time (10

seconds - 7 days).

• After each transmission, another transmission for that input is disabled for the paralysis time

(0 – 127.5 sec).

• PI2 can be scaled by a configurable divider.

The diagnostics functions of the WI-I/O K allow the user to manually set the counter values to
any value (refer section 5 of this manual). On initial start-up of the modules, the counter values
will be zeroed. If the module loses power, the WI-I/O K will save the counter values to non­volatile memory before shutting down - these values will be restored when power is restored.

2.4.3 Shaft Encoder Inputs

The two pulse inputs may be configured to control one up/down count value, for use with
quadrature and incremental shaft encoders. A shaft encoder is a transducer that measures level or
displacement, and has two pulse signals to indicate change of level and direction of change. Both
pulse inputs are read at the same time. The divider parameter on PI2 must be set to 1 for this
application.

If an incremental encoder is used, then the calculated count value is stored in PI1. If a
quadrature encoder is used, then the calculated count value is stored in PI2.

The counter value (or “level position”) can be manually set using the WI-I/O K diagnostics
features (refer section 5 of this manual). Initially the counter will need to be “zeroed” when the
shaft encoder is in the “zero level” position.

2.4.4 Pulse Rates

The rate of each pulse count is calculated and can be transmitted as internal analog inputs. The
rate is calculated on the increase of the base counter, not the rate of the input pulses. The
maximum count rate which can be calculated is 1000Hz. For PI1, this is the maximum pulse
rate that can be calculated. For PI2, a divider can be used for pulse rates more than 1KHz. The
pulse rate values can be scaled - that is, the user can configure what pulse rate (0.1 – 1000Hz)
corresponds to maximum analog value (20mA). Each pulse rate can be scaled individually.
Note that this is separate to the divider on PI2 count.

If the pulse inputs are configured for a shaft encoder, a pulse rate is still calculated -
corresponding to rate change of level. A zero rate (“steady level”) will correspond to a 50%
analog signal. The analog signal will be more than 50% if the level is increasing, and less than

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User Manual v1.9

50% if the level is decreasing. If an incremental shaft encoder is used, then the rate may be
scaled by scaling PRATE1. If a quadrature encoder is used, scale PRATE2. The scaling value
will determine both the 100% analog signal (e.g. 20mA) and 0% signal (e.g. 4mA). For
example, if a maximum pulse rate of 10Hz is configured, then the analog signal will be:

100% if the encoder increases at 10Hz 50% if the encoder pulse rate is 0

0% if the encoder decreases at 10Hz. 75% if the encoder increases at 5Hz

25% if the encoder decreases at 5Hz

Note that this is only true if the pulse inputs are configured for a shaft encoder. If standard pulse
inputs are used, then 0% analog signal will correspond to zero pulse rate (0Hz).

The pulse rates are treated as analog inputs and follow the rules for an analog input as described
below.

2.4.5 Analog Inputs

The analog input can measure from 0 – 24mA or 0 – 10VDC. Current or voltage input can be
selected by an internal selector (refer Installation section of this manual). The mA input can be
used for conventional 4-20mA signals or 0-10mA or 0-20mA. The voltage input can be used for
0-5 or 0-10VDC signals. The WI-I/O K unit is factory configured for a 4-20mA signal, however
the user can calibrate the unit for other ranges. The measurement resolution is 12 bit.

The analog input uses a “sample time” and “warm-up time” configured by the user. The sample
time (0 – 32727 sec or 9.1hours) “wakes” the WI-I/O K from sleep mode and turns on the analog
loop supply. The “warm-up time” (0 – 100 seconds) allows the transducer to reach rated
accuracy before the WI-I/O K makes a measurement of the analog signal.

For example, if the sample time is 30 minutes and the warm-up time is 10 seconds, then every 30
minutes, the WI-I/O K will turn on its analog loop supply and after a further 10 seconds, take a
measurement of the analog signal. After the measurement is taken, the WI-I/O K reverts to sleep
mode. The loop voltage available for a transducer is approx. 24VDC.

If the warm-up time is set to the same or more than the sample time, then the analog loop will be
on continuously, and the WI-I/O K will measure the signal based on the sample time. For
example, if the sample time is 10 seconds, and the warm-up time 20 seconds, then the analog
loop will be continuously active and a measurement made every 10 secs. If the sample time os
set to zero, then a measurement is made every cycle of the WI-I/O K - that is, 0.5 sec.

Note that continuous analog loop operation will result in a short battery life if a battery supply is
used. A solar panel and battery supply is suitable.

If an externally powered analog signal is connected, then the same measurement process as
described above occurs .

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WI-I/O 9-K v1.9

When the WI-I/O K takes a measurement, it will transmit the analog value if the value has
changed by more than the pre-configured sensitivity since the last transmission. The sensitivity
can be configured from 0.1% to 75% with a default value of 3%. If the change in the signal since
the last transmitted value is less than the sensitivity, then the WI-I/O K will not transmit the
analog value.

The sensitivity value should be selected which is more than the normal analog signal noise. If
the sensitivity is less than the signal noise, then the WI-I/O K will send a lot of un-necessary
transmissions, possibly resulting in jamming the radio channel.

An update transmission of the analog value will be transmitted if the analog value has not been
transmitted for during the user-configurable update period (10 seconds - 7 days). If an update
time of zero is selected, then no update messages will be sent.

If the update time expires since the last transmission, then the last measured value will be
transmitted - that is, a new measurement will not be taken. Normally the update time will be
much longer than the sample time. If the update time is less than the sample time, then update
messages may transmit the same value as the previous transmission, as a new measurement has
not yet been taken.

Overview:

• Measurements of the analog signal are determined by the sample time and warm-up time

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