Omron PLC B7AM-8B16

Omron PLC B7AM-8B16

Alarm Types

Each alarm can be independently set to one of the following 19 alarm types. The default is 2: Upper limit. (see note.)

Auxiliary outputs are allocated for alarms. ON delays and OFF delays (0 to 999 s) can also be specified.

Note:In the default settings for models with HB or HS alarms, alarm 1 is set to a heater alarm (HA) and the Alarm Type 1 parameter is not displayed.

To use alarm 1, set the output assignment to alarm 1.

Set 

value Alarm type

Alarm output operation

Description of function When alarm value X 

is positive

When alarm value X 

is negative

0 Alarm function OFF Output OFF No alarm

1 Upper- and lower-limit *1 *2

Set the upward deviation in the set point for the alarm upper 

limit (H) and the lower deviation in the set point for the alarm 

lower limit (L). The alarm is ON when the PV is outside this 

deviation range.

(default) Upper-limit

Set the upward deviation in the set point by setting the alarm 

value (X). The alarm is ON when the PV is higher than the 

SP by the deviation or more.

3 Lower-limit

Set the downward deviation in the set point by setting the 

alarm value (X). The alarm is ON when the PV is lower than 

the SP by the deviation or more.

4 Upper- and lower-limit 

range *1 *3

Set the upward deviation in the set point for the alarm upper 

limit (H) and the lower deviation in the set point for the alarm 

lower limit (L). The alarm is ON when the PV is inside this 

deviation range.

5 Upper- and lower-limit with 

standby sequence *1 *4 A standby sequence is added to the upper- and lower-limit 

alarm (1). *6

6 Upper-limit with standby 

sequence A standby sequence is added to the upper-limit alarm (2). *6

7 Lower-limit with standby 

sequence A standby sequence is added to the lower-limit alarm (3). *6

8 Absolute-value upper

limit

The alarm will turn ON if the process value is larger than the 

alarm value (X) regardless of the set point.

9 Absolute-value lower-limit The alarm will turn ON if the process value is smaller than the 

alarm value (X) regardless of the set point.

10Absolute-value upper

limit with standby 

sequence

A standby sequence is added to the absolute-value upper

limit alarm (8). *6

11 Absolute-value lower-limit 

with standby sequence

A standby sequence is added to the absolute-value lower

limit alarm (9). *6

12 LBA (alarm 1 type only)-*7

13 PV change rate alarm-*8

14 SP absolute-value 

upper-limit alarm

This alarm type turns ON the alarm when the set point (SP) 

is higher than the alarm value (X).

15 SP absolute-value 

lower-limit alarm

This alarm type turns ON the alarm when the set point (SP) 

is lower than the alarm value (X).

16 MV absolute-value 

upper-limit alarm *9

Standard Control Standard Control

This alarm type turns ON the alarm when the manipulated 

variable (MV) is higher than the alarm value (X). Heating/Cooling 

Control (Heating MV)

Heating/Cooling 

Control (Heating MV)

Always ON

17 MV absolute-value 

lower-limit alarm *9

Standard Control Standard Control

This alarm type turns ON the alarm when the manipulated 

variable (MV) is lower than the alarm value (X). Heating/Cooling 

Control (Cooling MV) Heating/Cooling 

Control (Cooling MV)

Always ON

18 RSP absolute-value 

upper-limit alarm *10

This alarm type turns ON the alarm when the remote SP 

(RSP) is higher than the alarm value (X).

19 RSP absolute-value 

lower-limit alarm *10

This alarm type turns ON the alarm when the remote SP 

(RSP) is lower than the alarm value (X)