Orbit Merret OM PROFI, User Manual

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10 | USER MANUAL OM PROFI
DESCRIPTION
OF COMMUNICATION
2.
2.2.4
CONNECTION OF OM XXX DEVICES TO THE INTERNAL OM PROFIBUS DATA CARD
Downloading from OM instruments is performed through the „0“ function. If the function is active, downloading
channel values from OM xxx instrument with set address is performed in cycles. Between downloadings there
is a delay inserted, which is set in „Transmission delay„ in EEPROM of the OM Profibus card.
No data is downloaded unless the „Flag“ value is set to 1 and the „Function“ and „Address“ values are identical
in both telegrams (the received and the transmitted).
The values are in Float (4 byte) format.
2.2.5
CHANGE OF RELAY OUTPUTS LIMIT MARGINS
Under item „Number of relays“ you learn how many and which relay outputs does the current instrument
contain. The value is determined according to the significance of individual bits from 0 to 7 if the instrument
contains relays 1 to 8.
In case there are relay outputs in the instrument, the limit margins may be readjusted. For values of the limits 1
to 8 the required values are entered in the Float (4 byte) format. The value is sent to the instrument after setting
the relevant relay bit in „Relay mask“. After recording the mask shoud restore the 0 value..
2.2.6a PROJECTION OF TEXT IN OM XXX INSTRUMENTS
Every OM xxx instrument supporting Profibus includes the option of text projection on display. Projection is
performed in cycles with delay „Transmission delay“ by means of command „100“. Displayed are the characters
stored under „Display text“. Projection is performed for characters with code > 31. First character < 31 terminates
the text processing and the text is sent to display. The stop character is tagged on to the previous character.
For projection of a 6 character text the text is displayed for approx. 2,5 s unless another command arrrives.
For projection of a text exceeding 6 character the text gets displayed for approx. 1minute.
For instruments with fewer than 6 characters the texts need to be completed from the front with gaps up to
6 characters.
2.2.6b PROJECTION OF NUMBERS IN OM XXX INSTRUMENTS
There are three options for projection of numbers in OM xxx instruments. Two apply solely for OM xxxRS instruments
(monitors and RS communication display devices).
1. Number projection (Float 4 byte) to set number of decimal places for a period of approx. 2,5 s.
Projection is performed through functions „10“ to „15“ (function „10“ = w/o d.p., „15“ = 5 decimal places).
Profibus card displays this data in cycles with inserted „Transmission delay“
2. Inserting and projecting decimal number (Float 4 byte) to OM xxx instrument through function „20“.
Number is sent to OM xxxRS instrument where the value is received and processesed:
Recalculates with the set minimum and maximum,
May be recalculated with linearisation table, Mathematic function
evaluates limit statuses, sets the analog output,
projects the value in relevant format,
allows for changing the display colour in relation to value significance
The value stays projected in the instrument until another value is recorded or the instrument switches off.