GEM80
5. Operation
Issue 002 (07/05)
Fieldbus Technical Manual T2035
Page 7
5.
Operation
5.1
Introduction
CAUTION
The inclusion and configuration of one or more FIELDBUS modules grants read
and write access to GEM80 data tables. It is the user’s responsibility to ensure
that adequate safeguards are used to prevent dangerous situations arising.
5.2
Module Configuration Parameters
An Advanced GEM80 Programmer (or equivalent) must be used to supply the module
configuration parameters. These parameters must be entered into the P-table of the
host GEM80 Controller by the user before the module can be used. The GEMLAN-T
Module accesses these parameters on behalf of the Fieldbus module(s) after
completion of its boot procedure. The GEMLAN-T Module takes approximately one
minute to complete its boot procedure.
Note:
If the parameters are subsequently altered, they will be recognised and
validated by the GEMLAN-T Module following a recompilation. During
the validation, Fieldbus communication is halted. If the validation
should fail, the communication remains halted.
Remember that P-table entries above P149 will only exist if specifically
declared in the user program.
For the GEMLAN-T module to access the configuration data successfully, a value must
be written into P74. This value acts as a pointer to the P-table location containing the
configuration parameters for Fieldbus module #1. Fieldbus module #2 parameters
follow those of module #1 in the P-table.
E.G. if P74 contains a value of 300, the configuration parameters start at P300.
Inserting a value of 0 into P74 renders inactive all Fieldbus modules of the host
controller.
A detailed description of each configuration parameter is provided in the following
paragraphs. Table 5-1 provides a reference table. Table 5-2 is an example of the use
of the P-tables.