EMS Manual

Distributor Commands and Responses
EMS Manual—426909-005
17-21
CONTROL Command (ZEMS-CMD-CONTROL)
messages. If you start a forwarding distributor without a filter, the distributor does not
begin event-message processing until a filter is specified.
To specify a single filter, use ZEMS-TKN-FILTERFILE, which contains the name of the
filter object-file. Use ZEMS-TKN-FILTERFILE to provide a first filter or to replace a
previously loaded filter.
To specify multiple filters, you must use the ZCOM-CMD-ADD, -ALTER, and
-DELETE commands, which support multiple objects. For more details, see Extended
Programmatic Interface on page 17-2 and the ZCOM-CMD -ADD, -ALTER, and
-DELETE command descriptions. The basic SPI interface supports the addition or
deletion of only one filter at a time.
If you have provided a printing or consumer distributor with a filter and want to reinstate
the default filter, use the ZEMS-TKN-RESET-FILTER token. The ZEMS-TKN-RESET-
FILTER token is not defined for forwarding distributors. If attempted, the error ZEMS-
ERROR-NULL-FILTER is returned.
When you specify a filter, you must specify any required filter parameters.
Passing Filter Parameters
An application can pass filter parameters that were previously declared in a filter
specification. For detailed information about these EMS filters, see Section 5,
Compiled Filters.
The application uses these tokens and the ZEMS-CMD-CONTROL command to pass
parameter tokens:

ZEMS-TKN-FILTERFILE to install a new filter

ZEMS-TKN-REPLACE-PARAM to replace the parameters of the current filter
Parameter tokens supplied in the CONTROL command message must match—in
token code and subsystem ID—the parameter tokens declared in the filter
specification. Optional parameter tokens (parameters declared “OPTIONAL” in the filter
specification) can be supplied or omitted. Required parameters must be supplied.
Treat filter parameters as a set; you cannot supply or replace them one by one. The
REPLACE-PARAM command removes the values for all existing parameters and
substitutes the submitted values.
Note. For new applications, you are strongly advised to use the distributor’s extended
programmatic interface commands (ZCOM-ADD, -ALTER, -DELETE) instead of the basic SPI
ZEMS- commands in all situations.
Note. For new applications, HP strongly advises using the distributor’s extended
programmatic interface commands (ZCOM-ADD, -ALTER, -DELETE) instead of the basic SPI
ZEMS- commands to submit filter parameters.