Bently Nevada 3300/01 Series, Operation Manual

Page: 40 / 78

• S y s t e m Monitor
•
•
16
80175-01
PROTOCOL SPECIFICATIONS
configuration of the rack is known, then the exact locations of all the rack's direct values can be
specified. A simple formula which can be used to calculate the starting address of monitor direct
values is
Starting address = 8 + 2(monitor slot number - 1) + 2(number of 6-channel temperature
monitors to the left of the selected monitor)
Use the Unprotected Read Command (command code 1) to access the direct values for the rack.
Example 1:
Read the direct values from a 3300 rack which contains 4 dual vibration monitors installed
in slots 1, 2, 3 and 4.
The message request should be an unprotected read command specifying 8 data words
(16 bytes) starting at word address 8. The Allen Bradley command format will have the
ADDR field set to 16 and the SIZE field set to 16. See note 2 above.
Example 2:
Read the direct values from a 3300 rack which has dual vibration monitors installed into
monitor positions 1 and 2 and a 6-channel temperature monitor in monitor position 5.
The data that we want consists of 10 values contained in nonsequential locations starting
at word address 8. To retrieve the data most efficiently we should request the first 14
words which will include the values for the empty monitor positions 3 and 4. The host
should then throw out the invalid data from monitor slots 3 and 4. The Allen Bradley
command format will have the ADDR field set to 16 and the SIZE field set to 28. See note
2 above.
Example 3:
Read the temperatures values from a 6-channel temperature monitor in slot 5 of a 3300
rack. This rack also has a 6-channel temperature monitor in slot 1 and 2 dual vibration
monitors in slots 3 and 4.
The starting word address for the temperature monitor in slot 5 is 18. This is the
33