OCEAN CONTROLS KTA-296 User manual

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•Extend analog or digital signals
wirelessly up to 40km line-of-sight
•2 x analog inputs (4-20mA, 0-5V, 0-10V)
•2 x analog outputs (4-20mA, 0-5V, 0-10V)
•2 x isolated digital inputs (2.5 to 30V)
•2 x relay outputs (240V; 5A)
•DIN rail mountable
•“Link OK” Digital Output
•24V DC Powered
The KTA-296 Wireless I/O extender pair offers a convenient way for analog or digital signals
to span large distances via a wireless link. The KTA-296 is designed to operate as a pair,
where the I/O from one unit “mirrors” the I/O from the other. That is, the digital inputs on
one unit trigger the relay outputs on the other unit, and the analog inputs on one unit sets
the analog outputs on the other.
I/O Mapping
Device 1
Device 2
Digital Input 1
Relay 1
Digital Input 2
Relay 2
Analog Input 1
Analog Output 1
Analog Input 2
Analog Output 2
Note: Digital Inputs 3 and 4, and Analog Inputs 3 and 4, are unused on the KTA-296.
The Digital Inputs are bi-directional, and optically isolated. They will suit NPN, PNP, and dry
contact style sensors up to 30V DC.
The digital outputs are mechanical relays rated up to 240V AC/30V DC and 5A. Optically
Isolated outputs are a non-standard option
The Analog Inputs by default suit 4 to 20 mA style instruments. 0 to 20 mA, 0 to 5V and 0 to
10V are non-standard options.
The Analog Outputs by default are 4 to 20 mA. 0 to 20mA, 0 to 5V, and 0 to 10V are non-
standard options.

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Quick Start Guide
The KTA-296 pair has been pre-configured in the factory with default settings. It is
recommended to leave the unit at default unless changes are necessary.
Default:
Poll time: 10s
Tx Power: 30dBm
Air Speed: 16
Ensure that antennas are plugged into the radio of each KTA-296. Apply power (24V DC).
Allow 5 minutes for the radios to detect each other and establish a link. The status LED can
be monitored for this purpose; if flashing, there are no communications, if solidly on, the
link is established and the KTA-296 is ready for operation. An open collector style digital
output is available at AI3 to indicate if the link is good.
Each radio also has a transmit and receive LED. These can be monitored to view traffic on
the wireless link and establish if the radios have found each other. See below for comms
details.
Device Overview
The KTA-296 operates as a pair. Packets are sent over the radio link to update each device
as inputs change. A change on the state of a digital input will trigger a packet to be
sent. A change in an analog input of more than 4% will trigger a packet to be sent.
Even if there is no change on the inputs, a packet will be sent as frequently as the “poll
time” to ensure that both devices remain in sync.
Should a device send a packet but not receive a response, it will try sending the packet up
to another 3 times. If there is still no response, the device times out and shows “comms
down” on the status LED.
To prevent radio traffic from becoming excessive, there is a minimum period that the radios
must wait before transmitting on the link. This period is random between 1 and 5 seconds,
and is changed after every packet is transmitted.

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Connections:
Name
Description
V+
12 or 24V DC power (depending on model)
GND
Ground
DI 1+
Positive side of optically isolated digital input 1*
DI 1−
Negative side of optically isolated digital input 1*
DI 2+
Positive side of optically isolated digital input 2*
DI 2−
Negative side of optically isolated digital input 2*
AO 1
Analog Output 1
AO 2
Analog Output 2
AI 1
Analog Input 1
AI 2
Analog Input 2
RELAY 1 NO
Normally Open contact of relay 1
RELAY 2 COM
Common contact of relay 1
RELAY 2 NO
Normally Open contact of relay 1
RELAY 2 COM
Common contact of relay 1
USB
Only used for firmware updates on the KTA-296
Radio
RFD900 long range radio transceiver (900MHz)
AI3
“Link OK” open collector output
* The digital inputs are labelled as positive and negative, but in practice polarity is not
important because they are bi-directional.
Leds:
Name
Description
RELAY 1
Indicates if relay 1 is on
RELAY 2
Indicates if relay 2 is on
RADIO
Shows the status of the radio after configuration:
•Off. Radio is ready to communicate at the default
comms settings.
•Solidly On. The radio has been initialised correctly
after configuration, and is ready to communicate
•Flashing slowly (once a second). No radio has been
found, or unable to communicate to the radio. Check

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to ensure the radio is properly plugged into the socket.
•Flashing quickly (ten times a second). Unknown error;
the radio has been found, but an error occurred when
initialising.
COMMS
Shows the status of the communications between the two
radios:
•Solidly On. Both devices are communicating
successfully
•Flashing slowly (once a second). Communications
timed out. The link is down or out of range.
•Flashing quickly (ten times a second). Bad or
unknown packet. A message was received, but it is not
in a format that is recognised or can be decoded.
TRANS
Transmit. Flashes every time a message is transmitted over
the radio link
RECEIVE
Flashes every time a message is received on the radio link
DIP switches:
(The enclosure will need to be removed to access)
Switch 1
Modbus Addressing
Switch 1
Modbus Addressing
OFF
Master = 1; Slave = 2
ON
Master = 2; Slave = 1
Switches 2 & 3
Poll time
Switch 2
Switch 3
Poll Time
OFF
OFF
5 s
ON
OFF
10 s
OFF
ON
15 s
ON
ON
20 s
Switch 4
Activate Config Mode

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Config mode is used to send a new set up to the radio module, using the RFD900 config
software (discussed in more detail below).
Switch 4
Radio Mode
OFF
Normal
ON
Config
Switch 5
Digital IOs behaviours if lose connection
Switch 5
Behaviours
OFF
The digital IOs will remain the
same if lose connection
ON
The digital IOs will reset if lose
connection
Other switches should stay OFF.

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RFD900 Configuration Utility
The factory default radio parameters for the KTA-296 should be adequate for most
applications. Having said that, it is possible to reconfigure these settings using the provided
utility.

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Steps:
1. Plug the KTA-296 into a PC via USB. Remove the lid and turn on switch 4. Apply
power.
2. Download and launch the RFD900 config utility from the Ocean Controls website.
3. Select the COM port that the USB is connected on using the dropdown box under
“connection”.
4. Set the following parameters (items in bold are mandatory, do not change):
•Baud rate: 57600
•Air speed: 16
•Net ID (default: 1): same as “channel.” If multiple radios are in range of each other,
they will need to talk on separate channels simiarly to a walkie talkie. Can be set
to any number, but each pair will need to be on the same channel to
communicate.
•Tx Power (default: 30 dBm). Transmit power. More transmit power generally
means better range, but more interference with other devices also transmitting
on 900MHz whithin range.
•Min Freq: 915000
•Max Freq: 921000
•Number of Channels: 20
•Duty Cycle: 100
•ECC: not ticked
•Mavlink: Mavlink
5. Press “Write Settings” to download to the radio. If successful, you will see “Done”
display in the messages window at the bottom.
6. Turn off switch 4 to return the radio to normal operation.