Table 2-51 Spp Inputs And Current State - Honeywell UMC800 Reference Manual

2.60 SPP Function Block,
Usage Tips
• If the first step of a profile is a ramp, the progrma will start the ramp from the value of PV Input 1. If the first step of a
profile is a soak, the program will start from the soak value. If consistent starting values are required, begin all profiles
with a soak.
• The PV inputs are used to determine PV–SP deviation for guaranteed soak segments.
• Valid program numbers begin with 1. Valid segment numbers begin with 1.
• The GHOLD output is not affected by the status of the GHOLD input.
• The RST, HLD, RUN, JOG, ADV, SET, RESTART inputs are activated only when the respective input changes from
OFF to ON. A maintained ON input has no different affect than a pulsed ON input (that is, it has no effect until it turns
OFF and then back ON again).
•The program may be changed (with some exceptions) from the current state to a new state by the operator as well as
by inputs to the SPP block. Table 2-51 lists the resulting states.
Input
RESET
RESET
RESET
HOLD HOLD
RUN
RUN
GHOLD RESET
•
Concerning changing program state, if more than one function block input is on in the same execution cycle, RESET
has priority over HOLD and RUN, and GHOLD has priority over RUN.
Also, function block inputs will override inputs from the Operator Panel that occur during the same execution cycle.
And finally, state changes from the Operator Panel are processed on the basis of the "last change wins."
• At the beginning of a segment, STME will be 0 for one execution cycle to permit start of segment detection by other
blocks.
• At the end of a segment, STMR will be 0 for one execution cycle to permit end of segment detection by other blocks.
• If RESTART is On, the block will use PV1 as a starting value and ramp at Restart Rate back to the last SP value, then
complete the remaining portion of the segment. Restart Rate is a property of the profile (program)
• "Fastforward" (i.e. Verify) is initiated through the operator interface using contained parameter FFW. It is not an input
pin.
Restart Scenario Options
Table 2-52 is a list of Restart Scenario options for the Setpoint Program.
No Action taken
1
2 Use the Restart feature of the Setpoint
Programmer with a configurable Ramp
Rate.
Use the Restart feature of the Setpoint
3
Programmer with a configurable Ramp Rate
and use a compare function so that the
restart will apply only after a certain time.
ATTENTION: Be sure to configure the Restart Ramp Rate when a controlled restart is being configured. If
not the default value of 0 will cause the programmer to freeze.
3/99
continued

Table 2-51 SPP Inputs and Current State

Current State
HOLD
RESET RUN
HOLD HOLD
RUN RUN
HOLD GHOLD
Table 2-52 Restart Scenario Options
Program will start at the point where it was prior to power
down.
This feature will use the PV (connected to PV1) as the initial
starting point for the Setpoint and will use a configurable
ramp rate for the profile. When the temperature gets to the
original Setpoint prior to power down, the program will
continue.
You may gate this Restart input to the programmer to only
apply after a certain time off and/or a certain segment if
desired using Compare function blocks.
Scenario B.
Function Block Reference Guide
RUN GHOLD
RESET
HOLD
GHOLD
GHOLD
See Figure 2-62, Scenario A.
Function Blocks
STOP
RESET
STOP
STOP
STOP
See Figure 2-62,
183