Communication Protocol
13
Table 2
Parameter Symbol
Value
Input Type
inp
pt100
,
pt1000
,
ptc1
,
ptc2
,
r.0.1k
,
t.c.b
,
t.c.j
,
t.c.k
,
t.c.r
,
t.c.s
,
t.c.t
,
u
,
u.0.10
,
i.0.20
,
i.4.20
Unit
unit c
,
f
Point Position
pnt
0
,
1
,
2
,
3
Input Low
i.hi -1999
...
9999
Input High
i.lo -1999
...
9999
Input Correction
i.cor -1999
...
9999
Address
addr 1
...
254
Baud Rate
baud
1200
,
2400
,
4800
,
9600
Gradient
grad 0
...
9999
Filter Time
f.t
0
...
999
Filter Band
f.b
0
...
M
Input Value
p.v
*
Error Info
error
**
*
Input Value
(read-only)
numerical value with ISU
- measured
input value
sat.lo
- ADC under-range
sat.hi
- ADC over-range
inp.br
- sensor break
break
- device failure
noise
- noisy measurement
**
Error Info
0
- initializes non-volatile memory
-1
- error
FAiL
(read-only)
1
...
29
- errors
ER01
...
ER29
(read-only)
Protocol architecture
♦
The protocol is based
on UART protocol with:
Baud Rate - as defined
by parameter
Baud Rate
;
Data bits - 8;
Parity Control - Even;
Stop bit - 1.
♦
ASCII protocol is used
for communicating,
and the information
is exchanged in frames.
♦
Each frame consists of 1,
or 2 words separated
by byte 32 (SPACE),
and ends with bytes 13 (CR)
and 10 (LF). The first word
in the frame denotes
the parameter 'Symbol'
as taken from Table 2 and
the second word (if needed)
is the parameter 'Value',
both spelled with only
small Latin letters, digits,
dots, and/or the '-' sign.
Device activating
♦
To respond to commands,
the device should be active.
♦
For a device to be activated,
it must receive a
U
х
command,
where '
х
' is the value
of the parameter
Address
or the value '255' (if device
address is unknown),
and respond to it with
ok.
.
♦
If a device does not respond
even to
U
255
, check
the UART protocol settings,
chiefly
Baud Rate
value.
