The protocol serves for controlling the PLC KOS 130 device from AEG. The CU exchanges messages with PLC KOS in short intervals, stores them into its flash memory and sends regular messages to the centre in longer intervals. In the case of a loss in communication with the PLC the CU sends a message to the centre immediately.
Data packet –
address | function | data | chs |
1 byte | 1 byte | 3 byte | 1 byte |
address – 7 bit. Eighth bit -1 – short message (e.g. 0xE3), 0 – long message (e.g. 63FA 3000 0056)
0 to 0x7E – max.number of stations is 127
7F – broadcast
function –
FA – administration message – there are no new messages
FB – general, general broadcast, restore
9B – command
8A – alarm – events transferred immediately
data –
message data, a longer message is split into 3-byte parts and more packets are transferred
11 bits (start bit, 8 bits data, odd parity, stop bit)
chs –
check sum
According to Obr.1 – call from the CU to the PLC for transferring a message and also the end of a message from the PLC –
0xE3
Communication between the centre and individual stations occurs at
pre-selected times to prevent the accumulation of messages at a single
instant. For that reason all CUs maintain synchronous time, via the
functions in menu (U)nit (e)dit.
Parameter (c)ycle
is used to set the time, e.g. 120
sec, over which all stations take it in turns to send a regular
administration message to the centre. Each CU sets
the instant of transmission automatically different based on the value of
the last byte of its address.
In addition restore messages are sent 1x per hour and general messages 2x per hour. Transmission times for sending these messages are set to selected minutes in the hour by configuration parameters. These times need to be selected in each CU differently, however, it is not considered a fault if two CU have the same time as the MORSE system will handle this.
The CU and PLC exchange messages 0xE3
(address + set upper bit ), in (c)ycle
an
administration message is generated informing the
centre that there are no new messages:
07:51:57.001 tx 1 | S01 E3 07:51:57.540 rx;i 1 | S01 E3 07:51:58.001 tx 1 | S01 E3 07:51:58.539 rx;i 1 | S01 E3 07:51:59.002|690F00FF 690F0063|690F00FF 690F0063|R01I IN 6N89 6dat 63FA 3000 0056 07:51:59.539 rx;i 1 | S01 E3 07:52:00.000 tx 1 | S01
The connection to the PLC is interrupted.
After a delay defined by (f)ail count
an alarm
KOS fault ON is generated.
07:52:06.001 tx 1 | S01 E3 07:52:06.540 rx;i 1 | S01 E3 07:52:07.001 tx 1 | S01 E3 07:52:07.223 --- 0 | S01;RX BREAK 07:52:08.001 tx 1 | S01 E3 07:52:09.001 tx 1 | S01 E3 07:52:09.302|690F00FF 690F0063|690F00FF 690F0063|R01I IN 6N89 7dat 638A 0F80 0099 07:52:10.001 tx 1 | S01 E3 07:52:11.001 tx 1 | S01 E3 07:52:12.001 tx 1 | S01 E3
SEAB parameters: (a)ddress RTU:0063 a(d)dress CENTER:00FF (p)oll:1000ms (t)imeout:300ms (c)ycle:20s (f)ail count:3 (b)cast:0001 (G)A:1 GAtim(1):12min GAtim(2):42min (R)T:1 RTt(i)m:20min (A)dm:1 f(w)size:0000 (q)uit >>
(a)ddress RTU:0063
– lower 1st byte of address of CU and PLC
a(d)dress CENTER:00FF
– lower 2nd byte of centre address
(p)oll:1000ms
– period of communication between CU and PLC
(t)imeout:300ms
– delay in waiting for a response from PLC
(f)ail count:3
– number of delays(t)imeout
, following which the alarm is generated
(c)ycle:20s
– length of the cycle for an administration message, a greater value than the number of stations is selected in sec
(b)cast:0001
– receipt of broadcasts0 – not permitted
1 – permitted
(G)A:1
– general message –0 – not permitted
1 – permitted
GAtim(1):12min GAtim(2):42min
– selection of minutes each hour when the general message is sent
(R)T:1
– restore message0 – not permitted
1 – permitted
RTt(i)m:20min
– minute each hour when the restore message is sent
(A)dm:1
– administration message in case there are no new messages is –0 – forbidden
1 – permitted
f(w)size:0000
– diagnostics data about the immediate length of data ready in Flash memory (in words)