Baumer GE-GB-GXxxx - Manual (Page 40)

Manual_ProfibusDPV2_BIDE_EN.docx 40/41 Baumer IVO GmbH & Co. KG
22.11.12 Villingen-Schwenningen, Germany
8.2.4. How to alter the resolution ?
The encoder resolution in steps per revolution („Measuring units per revolution“) is programmed during
projecting by parameterization of the PROFIBUS slave in the PROFIBUS project.
Normally this is performed by the control’s projecting software (for example Siemens Step7) using a PC.
The encoder resolution is programmable in individual steps between the maximum limit (encoder-specific, for
example 8192 at GXMMW) and the minimum limit of 1 step/revolution.
Important: The encoder’s total measuring range (units, “hi/lo“) must be adapted to the programmed
resolution. If not, this will result in parameterization errors indicated by the LED in the bus cover flashing red.
The maximum total measuring range is calculated by multiplying the resolution (steps per revolution) by the
maximum number of revolutions the encoder is capable of.
8.2.5. How to read diagnostic data out of the control?
There is no device-specific diagnosis for DPV2 encoders as known by DPV0 encoders. Diagnostic operations
are performed in line with the DPV2 encoder profile as module-relevant diagnosis according to alarm model
DPV1.
8.3. FAQ: Troubleshooting
8.3.1. No encoder communication (LED yellow continuous)
The encoder connected is not recognized in the bus. No configuration nor parameterization, the LED is yellow
continuous.
This phenomenon may be due to the following reasons:
PROFIBUS not connected or broken wire.
PROFIBUS is connected but lines A and B were confused. Original PROFIBUS cable provides green for
line A and red for line B.
The PROFIBUS node ID set by BCD switch in the bus cover does not coincide with the PROFIBUS
system parameterization. Please verify upon coincidence. Encoder default setting upon delivery is 00.
Node IDs 00, 01 and 02 are often reserved to masters and not common for slaves. Mind the orientation of
the tens digit (left) and units digit (right) when zero is on top the BCD switches.
Incorrect encoder implementation in the PROFIBUS project, now the control does not know it exists.
Correct encoder implementation in the PROFIBUS project, but accidentally the compiled project has not
yet been transmitted to the control.
Bus termination incorrect. If the encoder is the final device in the bus it has to be terminated by resistor.
Terminating resistors are integrated in the bus cover and connected by two-pole DIP switch. Do not utilize
so-called PROFIBUS D-SUB connectors for bus termination. Due to missing bus reference voltage it is
only a passive termination that rather would disturb the bus.
In particular baud rates of 6 and 12 MHZ call for proper bus termination. Stub and branched lines are
generally not allowed.
Should the above troubleshooting be unsuccessful, try to connect the encoder by the other two bus
terminals A and B. Try also another node ID at the BCD switches, for example 22, 44 or 88 to exclude any
additional problem.