User manual - COUNTER SLIK-638
Principle of operation of batcher function from example 3
After press of [
START pouring
] button (Figure 6.3) offset value is showed on the
display, next (while pouring) display shows how much water remains to pour. Start causes of
closing of both relays – both valves are opened. Flow meter generates pulses delivered to
counting input
{ B }
, so counter decreases it's value. When counter down counts below
threshold
“SEtP1”
value (in example it is value 6.0), then relay 1 will be opened – main valve
will start to close itself. Closing process need about 0.5 sec, so about 3L of water will flow
during this time via main valve. Pouring is being continued, via additional valve. When counter
will down count below threshold
“SEtP2”
value (in this example 0.3), relay R2 will be opened –
additional valve will start closing, it takes about 0.5 sec. About 0.3L of water will flow during
this time, what ends pouring. After that counter should show 0.0 (or value very close to 0.0).
Next pouring cycle can be initiated by [
START pouring
] button.
9.
THE MODBUS PRO
TOCOL HANDLING
Transmission parameters: 1 start bit, 8 data bits, 1 or 2 stop bit (2 bits are send, 1 and 2 bits
are accepted when receive), no parity control
Baud rate:
selectable from: 1200 to 115200 bits/second
Transmission protocol:
MODBUS RTU compatible
The device parameters and display value are available via RS-485 interface, as HOLDING-
type registers (numeric values are given in U2 code) of Modbus RTU protocol. The registers
(or groups of the registers) can be read by 03h function, and wrote by 06h (single registers) or
10h (group of the registers) accordingly to Modbus RTU specification. Maximum group size for
03h and 10h functions can not exceeds 16 registers (for single frame).
The device interprets the broadcast messages, but then do not sends the answers.
9.1.
LIST OF REGISTERS
Register Write
Range
Register description
01h
1
No
see descr. Display value - higher word.
02h
1
No
see descr. Display value - lower word.
03h
No
see descr.
The status of the displayed value:
0000h
- data valid,
0080h
- overflow, warning “
-Hi-
” is displayed
0040h
- underflow, warning “
-Lo-
” is displayed
04h
2
Yes
see descr.
State of precounter - this is internal modulo
N
counter, where
N
=
“div”
, overfill of this counter causes incrementation/decrementation of
main counter.
05h
2
Yes
see descr. State of precounter (low word)
06h
2
Yes
see descr. Main counter value - high word
07h
2
Yes
see descr. Main counter value - low word.
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