Yokogawa DO202 2-Wire Dissolved Oxygen Analyzer - Manual (Page 64)

4-6 Profibus
IM 12A00A01-61E
IMPORTANT
Connecting a Profibus configuration tool to a loop with its existing host may cause communication data
scrambles resulting in a functional disorder or a system failure.
4-3-2 Host Setting
To activate Profibus, the following settings are required for the host.
IMPORTANT
Do not turn off the power immediately after setting. When the parameters are saved to the EEPROM, the
redundant processing is executed for an improvement of reliability. If the power is turned off within 60 sec-
onds after settings are made, the modified parameters are not saved and the settings may return to their
original values.
For cyclic data communication a GSD file is required. This file contains all necessary information to start
this type of communication. Please make sure the gsd file is in the right directory so the information is avail-
able to the HOST. Refer to the HOST’s manual for guidance.
For acyclic communication several configuration tools can be used. Each communication tool requires
it’s own device driver. We currently support only Siemens Simatic PDM. All parameter lists and methods
described in this manual are based on this acyclic communication tool. Please make sure the device driver
is in the proper directory. Most HOST systems come with an “install device driver” package which places all
required files in the designated folders.
4-3-3 Bus Power ON
Turn on the power of the host and the bus. First all segments of the display are lit, then the display begins
to operate. If the indicator is not lit, check the polarity of the power supply.
Using the host device display function, check that the EXA is in operation on the bus.
Unless otherwise specified, the following settings are in effect when shipped from the factory.
If no EXA is detected, check the available address. Please set all addresses of the devices in advance or
separately connect each EXA and set a different address for each. Make sure to note the address after
changing it as from this point on the device can only be accessed through this address.
4-3-4 Reading cyclic parameters
In general, slave devices exchange data cyclically with the master (class 1, e.g. PLC). The EXA (slave) gets
the data from the sensor, makes some calculations and makes the outcome available through analog input
blocks. The controller device (Master) requests for these process values, makes some calculation (PID,
ratio) and sends the result to an actuator. The EXA contains three analog input blocks and therefore three
Process values for cyclic data transfer.
The master class 1 device gets the information (of the EXA) by consulting the GSD file. A device specific
GSD file should be available for each device and should have an unique identifier. All information necessary
for cyclic data transfer is described in the GSD file. The YP01078X.gsd file and a bitmap file YP01078X.dib
(device independent bitmap) should be placed in dedicated folders (“directories”). Refer to the manual of the
Master Class 1 device for these folders. With these files, the Master Class 1 devices are able to start cyclic
data transfer.