Tempco TEC-2500, Instruction Manual

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SP2F Function:
Defines the format of SP2 value. If ACTU is selected for SP2F
in the setup menu, the event input function will use the SP2 value for its second
set point. If DEVI is selected for SP2F, the SP1 value will be added to SP2. The
sum of SP1 and SP2 (SP1+SP2) will be used by the event input function for the
second set point value. In certain applications, it is desirable to move the
second set point value with respect to the value of set point 1. The DEVI
function for SP2 provides a convenient way to do this.
Modification from RS-232 to event input:
Because of the limited number of pins, pin 11 is used for both event input and
RS-232. If you want to change function of the TEC-2500 from RS-232 to event
input, you must modify jumpers J51 and J52 on the CPU board by opening
jumper J52 and shorting jumper J51. Refer to section 2-16 for the location of
jumpers J51 and J52.
4–2 Second Set Point
In certain applications it is desirable to have the set point change automatically,
without the need to adjust it. You can apply a signal to the event input terminals
(pin 10 and pin 11). The signal applied to the event input may come from a
timer , a PLC , an alarm relay , a manual switch, or other devices. Select SP2
for EIFN, which is in the setup menu. This is available only when SP1.2, MIN.R,
or HR.R is used for SPMD, where MIN.R and HR.R are used for the ramping
function. See section 4-4.
Application 1: A process is required to be heated to a higher temperature as
soon as its pressure exceeds a certain limit. Set SPMD=SP1.2, EIFN=SP2 (or
SP.P2 if the second PID is required for the higher temperature too). The
pressure gauge is switched ON as it senses a higher pressure. Connect the
output contacts of the pressure gauge to the event input. SP1 is set for a
normal temperature and SP2 is set for a higher temperature. Choose ACTU for
SP2F.
Application 2: An oven is required to be heated to 300°C from 8:00AM to
6:00PM. After 6:00PM it should be maintained at 80°C. Use a programmable 24
hour cycle timer for this purpose. The timer output is used to control the event
input. Set SPMD=SP1.2, and EIFN=SP2 (or SP.P2 if the second PID is
required to be used for the second set point). SP1 is set at 300°C and SP2 is
set at 80°C. Choose ACTU for SP2F. After 6:00PM the timer output is closed.
The event input function will then select SP2 (=80°C) to control the process.
Refer to section 4-1 for more descriptions about SP2F function.
SP2F=Format of SP2 value
ACTU: SP2 is an actual value
DEVI: SP2 is a deviation value