6

STEP 5 PROGRAMMING THE ALARMS

USER INPUT MODE OPERATION

INPUT

ACTION

INPUT

ACTIVATION

AUTOMATIC ALARM

LATCHED ALARM

IN ALARM REGION

OUTSIDE ALARM REGION

IN ALARM REGION

OUTSIDE ALARM REGION

Reset

Edge

No action

Resets and puts the alarm in

Standby mode; resets alarm if in

Hysteresis band

Resets alarm if on

Set

Edge

No action

No action

No action

Sets alarm latched

Reset

Level

No action

Resets alarm while input is active,

resumes normal operation when

input is inactive; resets alarm if in

Hysteresis band

Resets alarm if on

Set

Level

No action

No action

Sets alarm latched

Resets and puts the alarm in

Standby mode; resets alarm if in

Hysteresis band

Action: Alarm 1 can be programmed for 5 modes of operation, Alarm 2 has 9 possible modes. See

Setpoint Alarm figures for illustration.

Manual: In Manual mode, the Alarms are forced on and off by writing ‘0’ or ‘1’ to the appropriate

MODBUS register (Alarm 1 state = 40027, Alarm 2 state = 40028). The alarms are

configured for this action from the factory. In this mode, the alarms will not respond to their

setpoint or hysteresis values.

Absolute HI: (with balanced or unbalanced hysteresis) The Alarm energizes when the Temperature

Value exceeds the Setpoint Limit Value.

Absolute LO: (with balanced or unbalanced hysteresis) The Alarm energizes when the Temperature

Value falls below the Setpoint Limit Value.

Deviation HI, Deviation LO, Band Inside or Outside: In these modes, Alarm 2 “tracks”

Alarm/Setpoint 1.

Setpoint: The alarm Setpoint value, entered in degrees. If the ITMS is programmed for mV or resistance modes, then the Setpoint is in mV or Ohms,

respectively.

Hysteresis: Hysteresis is used to eliminate output chatter. The Hysteresis Amount is the difference between the points where an Alarm will turn on

and turn off. In Unbalanced modes, the alarm turns on at the Setpoint, and turns off at Setpoint minus hysteresis for HI alarms, and Setpoint plus

hysteresis for LO alarms. In Balanced modes, the hysteresis is evenly divided above and below the Setpoint value. (See the Setpoint Alarm

Figures.)

Note: The Setpoint, along with the Hysteresis, MUST NOT produce a “trigger point” higher than 32,000, or less than -32,000. (See the Setpoint

Alarm Figures.)

Trigger Points: Trigger Points are the Process Values where the alarm state changes. Their values cannot be entered directly, but are shown as a

reference in the SFIMS software. The Setpoint Value, Hysteresis Value, and Setpoint Alarm Type determine the trigger points. With Deviation or

Band modes, Setpoint 1 and Setpoint 2 are combined to determine the trigger points. Trigger Points cannot be greater than +32000 or less than -

32000. If these limits are exceeded, the alarm is disabled and an alarm threshold over range error is set. The Trigger Points can be outside the

Temperature Value range for a given sensor type without receiving an error, but the alarm will not change state for that trigger point.

Reset: The alarms can be programmed for Automatic or Latched. In Automatic mode, an energized alarm turns off by itself once the Process Value

leaves the alarm region. In Latched mode, an energized alarm requires a reset from the User input, or a serial reset command. This is done by

writing a ‘0’ to the appropriate MODBUS register. (Alarm 1 state = 40027, Alarm 2 state = 40028)

On Delay: The time, in whole second increments, that the alarm will take to energize when the Process Value enters into an alarm region.

Enable Standby Delay: Standby prevents nuisance (typically low level) alarms after a power up. After powering up the unit, the temperature must

leave the alarm region. Once this has occurred, the standby is disabled, and the alarm responds normally until the next module power up.

User Input Action: The User Input can be programmed to Reset, or Set, either Alarm 1, Alarm 2, or both. The User Input is activated when terminal

6 is pulled low. (Connected to the Common terminal 12.)

User Input Activation: The User Input can be programmed to respond as a Level (maintained) or Edge (momentary) input. See the User Input Mode

Operation Table below.

Sensor Failure Action: This setting allows different alarm responses when the temperature sensor fails. The ITMS can be programmed to turn one

or both alarms on or off.

Sets alarm while input active,

resumes normal operation when

input is inactive

Resets alarm while input is active,

resumes normal operation when

input is inactive; resets alarm if in

Hysteresis band