Siemens SIMATIC 505 - Overlapping Cycle; Module Sample Rate

Selected Functions
5-2
5.1 Overlapping Cycle
The overlapping cycle functionality of the T urboPlastic module provides the
capability to perform plasticate during the clamp open profile, and part
removal in addition to the normal plasticate profile.
The feature is activated by setting bit numbers 4, 5, and 6 of word WY8 to 1
which enables plasticate, clamp open, and overlapping cycles.
When bit number 6 of word WY8 is set, a cure timer* determines when the
clamp opening cycle begins. (A cure timer determines the completion of the
plasticate cycle in the non-overlapping mode.) The cure timer is located at
position number 135 in the download table, which is the third value in the
plasticate portion of the table.
If the appropriate bits are set, and the cure timer is set to a value that is
less than the time required for plasticate to complete, then the clamp opens
and overlap occurs. If the cure timer is set to a value greater than the time
required to complete plasticate, then the clamp is held closed until the cure
timer expires, and no overlap occurs. Even though the cure timer has
expired and clamp close has completed, the plasticate cycle continues to run
if required to do so by the plasticate profile.
During execution, instructions are read from the PLC and status
information is reported back to the PLC. Exceptions to the normal
(sequential) operation are described in paragraphs 5.1.1 and 5.1.2.
5.1.1
The sample rate for the nonconcurrent portions of operation for both the
plasticate and clamp close profiles is determined by the values of W ord #1 in
their respective download tables. However , during the overlapping portions
of the cycle, the sample rates are added together , thereby increasing the
module scan time to a value equal to the combined values.
Example:
Plasticate sample rate (V133) = 5000 or 5 ms
Clamp open sample rate (V177) = 3000 or 3 ms
Module scan time during plasticate only = 5 ms
Module scan time during plasticate and clamp = 8 ms
Module scan time during clamp open only = 3 ms
* See List of T erms in Chapter 1 for description of cure time.
Module Sample
Rate