BASI BTC284U Operation Manual Download Page 2

 
 

Overview 

 

BTC284U is a low-cost multifunctional 
programmable controller. Its universal 
input accepts the most common RTDs, 
thermocouples, and linear signals. 
The device can be equipped with up 
to 2 relay outputs, which can control 
various actuators using ON/OFF 
control algorithm, and an optional 
RS485 interface enables networking. 
BTC284U allows adjusting of the built-in 
digital filters and the programmable 
output delay, resulting in increased 
operation reliability in case  
of industrial interferences. 

 

 
 

Input Setting 

    

 

    

 

 

 

Open the case. 

 

Follow the diagrams on the left 
to find the configuration jumpers 
J1 and J2, located on the main 
board (cases 'B', 'H', 'V', 'L', 'R1' 
and 'R1') or on the outer side  
of the right board  
(cases 'Q' and 'S'). 

 

To set input 0...10 V,  
short out J2. 

 

To set any of the other possible 
input types, short out J1. 

 

 
 

Waste Disposal 

15 

 

Do not dispose of 
electronic devices  
together with  
household waste  
material!

 

If disposed of within European Union,  
this product should be treated  
and recycled in accordance with the laws
of your jurisdiction implementing  
Directive 2012/19/EU on waste electrical 
and electronic equipment (WEEE).

 

 

 
 

Communication Protocol 

14

 

 

Notes: 

 

BTC284U adds 3 spaces 
in the beginning of the response. 

 

BTC284U returns decimal point 
even when the value is integer. 

 

#13 (CR) is byte 0x0D; 
#10 (LF) is byte 0x0A. 

 

The 

U

255

 command should be used 

only in case just one slave is presented. 

 

Protocol examples: 

PC or other device: 

  BTC284U response: 

activating device number 10 

U10#13#10  

ok.#13#10 

reading filter time 

f.t#13#10 

 f.t  0015.#13#10 

writing filter time of 30 

f.t 30#13#10 

 f.t  0030.#13#10 

reading input value of 27.5 

p.v#13#10 

 p.v  027.5#13#10 

 

 

invalid command. 

command not recognized 

parity error. 

parity error detected 

not a number. 

attempt to write symbols 

for numerical parameter 

point error. 

value resolution greater 

than parameter’s one 

out of range. 

value out of range 

unit is busy. 

writing is allowed only  

to device at Basic level 

read only. 

parameter is read-only 

can't save. 

problem with writing 

in non-volatile memory 

 

 

The device remains active  
until it receives another 

U

х

 

command, but with different 
device address, a 

FAiL

 

error, or with reset. 

 

Any 

Baud Rate

 value change 

through the communication 
interface also deactivates 
the device. 

Reading from a device 

 

If the frame consists of only 
one word, it is recognized  
as a command for reading.  

 

The device responds to it by 
returning the same word and 
its value, according to Table 2. 

Writing in a device 

 

If the frame consists of  
two words, it is recognized 
as a command for writing. 

 

With writing, transferred  
are the same two words 
that would have been 
received at the respective 
command for reading  
from the device.  

 

After successful writing, 
the device responds with 
the respective command  
for reading, except for 
the 

baud

 

command. 

Other device responses 

 

When 

Error Info 

value is 

-1

,  

the device substitutes any 
command for 

error

 reading. 

 

BTC284U responses in case
of incorrect protocol use  
are given on the left. 

Reset 

To reset the device,  
send command

 

reset

.

 

 

 
 

Mounting 

 

Panel mounting ('B' / 'H' / 'V' / 'Q' / 'S' / 'L')

 

 

Place BTC284U into an appropriate panel cut-out. 

 

Tighten it into place using 
the enclosed mounting bracket(s).

 

Rail mounting ('R1') 

 

Insert the upper rail edge into the upper 
plastic groove of the rail-installing mechanism 
on the back side of the unit.  

 

Press the unit towards the lower 
rail edge until the moving part  
of the installing mechanism clicks. 

Rail mounting ('R2') 

The device can be easily mounted on every  
35 mm rail conforming to EN50022 by the means 
of a standard UNDECAL socket base.

 

 

 
 

Electro-Magnetic Interference (EMI) Issues 

 

Important note: 

A built-in RC noise 
suppression circuit is 
connected in parallel 
with relay contacts. 
Full AC voltage  
isolation is NOT 
provided when relay 
contacts are open. 
Small AC current 
(

 1.5 mA at 230 VAC) 

still flows through 
the RC circuit!

 

 

All signal wires must be shielded. They must 
not be packaged together with power cables! 

 

Never lay the signal wires close to inductive or 
capacitive noise sources, such as relays, 
contactors, motors, etc.! 

 

All shields have to be grounded ONLY at one end, 
as closer as possible to the controller terminals! 

 

Avoid sharing supply lines with powerful 
consumers, especially with inductive loads, 
switched on and off.  

 

To stop unwelcome interference signals 
entering through the power supply lines,  
use shielded 1:1 isolation transformer! 

 

Shunt all switched (not only those switched  
by the controller) inductive consumers with 
special suppression networks: RC group and 
varistor - for AC loads, or diode - for DC loads.  

 

If the controller operates in a very powerful 
EMI area, it has to be mounted inside  
a grounded metal shielding box! 

 

To protect the interface from electro-magnetic 
disturbances, follow the RS485 standard 
guidelines. 

 

 

'B' / 'H' / 'V' 

'R1' 

'L' 

'S' 

'R2' 

'Q' 

Reviews: