Lake Shore Model 340 Temperature Controller User’s Manual
Instrument Programming
8-9
8.3.1.9 Settle
Temperature control systems often need time for temperature control to stabilize or temperature gradients to
settle out. The Settle instruction is used in a program to add a time delay or let the control temperature settle.
Hours:
Hours to wait (0 to 23).
Minutes:
Minutes to wait (0 to 59).
Seconds:
Seconds to wait (0 to 59).
Band:
Temperature threshold for stability, positive peak
value from 0 to 10 K with 0.1 K resolution.
To wait for control stability, the time parameters and Band are used together to set the stability criteria.
Stability is reached when the temperature of the control input sensor does not deviate from the setpoint by
more than the Band value for the set time. The Band is set in Kelvin. The setpoint units must be in
temperature for this instruction to operate.
8.3.1.10 Repeat/End
Repeat
The Repeat and End Repeat instructions work together to allow repetitive operations without repeating
instructions. The Repeat instruction is placed at the beginning of a group of instructions that are repeated and
the End Repeat is placed at the end. The group of instructions is repeated as many times as the user
specifies in the count parameter of the Repeat instruction.
Count:
Number of times to repeat the instructions between
this instruction and its appropriate end repeat.
Infinite Loop:
Repeat the instructions an infinite amount of
times; On or Off.
NOTE:
Nest up to 10 Repeat/End Repeat sets.
8.3.1.11 Call
The Call instruction provides a way to put small programs together into a larger program. A set of often
repeated instructions, called a subprogram, may be entered into a program location. Another program, called
a main program, can call one or more subprograms in any sequence.
A subprogram must occupy an entire program location. It can only be called from the beginning of the
program location and must run to the End instruction which returns control to the calling program. A
subprogram can call another subprogram but should not call itself or a subprogram that calls it.
The main program is in the program location that is run from the internal program setting screen. It begins
with the first instruction in the program location. The program in location 1 does not have to be the main
program. The internal program stops when it reaches the End instruction of the main program.
Program:
Program location to be called.
8.3.1.12 End
An End instruction is included in each of the 10 program locations. It does not take any of the 100 instruction
memory locations. When a program location is empty, the End instruction occupies the first instruction line.
When a program runs from the internal program setting screen, the instrument processes each instruction in
sequence until it reaches the End instruction where the program stops, then returns to normal operation.
Parameters (like setpoint and P, I, and D values) set in the program retain the last value set by the program.
If using the Call instruction is used, the End instruction returns control to the calling program.
End >|
8.3.1.13 NOP
The NOP instruction holds only memory space. When a running program encounters a NOP instruction, it
ignores it, but the instruction occupies a memory location. The instruction is most often used to save a
memory location in a for another instruction to be selected later.
NOP >|
Settle >| Hours: 0
| Minutes: 0
| Seconds: 0
| Band:
±0.00000K
Repeat >| Count: 1
|Infinite Loop: OFF
End Repeat >|
Call >|Program: 1