Elektro-Automatik IF-U1 Benutzerhandbuch Seite 86

Programming
We now send one byte to ID 0x0B. The CAN message has
to look like this:
02 0B 01 47
Object 71 (0x47), queries actual values
Data length = 1
Identifier
Attention! This is NOT the bit combination of the CAN
message which is truely sent over the CAN bus. A
CAN controller merges various bits into it and adds a
checksum to it. These are only the bytes that are sent
to the CAN controller unit.
An answer to this query could look like this:
02 0B 06 64 00 0A 00 42 AA
Same identifier, data length is 6, because three actual value
of 16 bits size each are sent. The actual values are transmit-
ted as percentage values and need to be translated to real
values. See section „7.7 Translating set/actual values" for
details. For an EL 9080-00 the actual values would trans-
late to 100% for voltage (=80V), 10% for current (=0A) and
66,7% for power (=1600W).
The nominal values for power, current and voltage can be
read out from the device with the proper objects and used
to translate the actual values to real values.
9.2.1 The time format
The time format represents times from 1µs to 100h by a 16
bit value. Such time stamps are checked by the device they
are sent to for being correct. Values that are too high or too
low are not accepted and will return an error message. The
upper 4 bits are used as a mask to determine the time range,
the rest of the bits represent the time value. This time format
is used to write (i.e. set) or read time values.
It applies for any device that feature a function related to
time, as long as this time values is settable/readable. The
resolution of the time ranges in the table below does not
necessarily match the resolution of the device they're sent
to. In this case, the values are rounded down. An example:
a time value of 0x3E7 is sent. This represents 999 x 1µs =
999µs. The manually adjustable time value of the device in
this time range is but 0.95ms or 1ms. The 999µs are rounded
down to 950µs. Hence there will be 0x3B6 returned (=950)
when read back, instead of the sent 0x3E7.
Not all devices use all of the masks in the table below.
Mask *
Bits 15..13 or 15..1
(1 (
0x000
(1
0x3000
(
0x6000
(1
0x7000
(
0x0000
(1
0x4000
(1
0x8000
(1
0x9000
(
0xC000
(1
Table: Time format
* If the mask is used to translate time values into real time, either bits 15...13 or 15..1 are relevant, depending on the used time range
© 009, Elektro-Automatik GmbH & Co. KG
Time value (bits 11..0)
min.(dec) min.(hex) max.(dec) max.(hex)
0 0x00
100 0x64
100 0x64
100 0x64
0 0x00
100 0x64
1 0x01
100 0x64
60 0x3C
For electronic loads and the rise time (object 92) applies,
according to the big table below:
Time range
30µs ... 99µs
0,10ms ... 0,99ms
1,0ms ... 9,9ms
10ms ... 99ms
100ms ... 00ms
** Values differing from the step width are rounded
For electronic loads and the pulse width (objects 90 and
91) applies, according to the big table below:
Time range
0,05ms ... 0,95ms
1,00ms ... 9,95ms
10ms ... 99,9ms
100ms ... 999ms
1,00s ... 9,99s
10,0s ... 100s
** Values differing from the step width are rounded
Example 1: the rise time for an electronic load shall be
set to 75ms. The step width of the time range on the load,
where the 75ms belong to, is 1ms. So we need to use the
0x6000 time range. Its resolution is 0.1ms, so it results in a
time value of 750 (75ms : 0.1ms). This translates to 0xEE.
Together with the mask you get a value of 0x6EE as time
value for the rise time (object 9).
LabView users need to provide the time in a different way,
see VI documentation.
Example 2: the time value of the battery test (only with elec-
tronic loads) has been read and shall now be translated to the
normal time format. The overall resolution of the battery test
time is 1s. Since the time ranges allow 1s resolution only up
to 1h, the time above 1h is given in minutes and hours.
A value of, for example, 0x8743 would translate into 1859s
or 30m59s, whereas a value of 0xC53 would translate to
1330m or h10m. The seconds are omitted in this time
range, so you would always read out the same time value
during 1 minute.
Resolution Resulting time range
999 0x3E7 1us
999 0x3E7 10us
999 0x3E7 100us
999 0x3E7 1ms
4999 0x1387 ms
5999 0x176F 10ms
3599 0xE0F 1s
1000 0x3E8 100ms
5999 0x176F 1m
Step width Mask for time range**
of device
1µs 0x000
10µs 0x000
100µs 0x3000
1ms 0x6000
1ms 0x7000
Step width Mask for time range**
of device
50µs 0x000
50µs 0x3000
100µs 0x6000
1ms 0x7000
10ms 0x4000
100ms 0x9000
0 ... 0,999ms
1ms ... 9,99ms
10ms ... 99,9ms
100ms ... 999ms
0 ... 9,998s
1,00s ... 59,99s
1s ... 59min:59s
10,0s ... 100,0s
01:00h ... 99:59h
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