Limit, Swap limit

Limit 1 (index 0x80n0:13) and Limit 2 (index 0x80n0:14)

The indices 0x80n0:07 or 0x80n0:08 serve to activate the limit value monitoring.
The limit values are entered for limit 1 in index 0x80n0:13 and for limit 2 in index 0x80n0:14.
If the limit values specified in the indices 0x80n0:13 and 0x80n0:14 are exceeded or not reached, the bits in the indices 0x60n0:03 and 0x60n0:05 are set accordingly (see example for EL3062).
Output limit n (2-bit):

0: not active
1: value is smaller than the limit value
2: value is larger than the limit value
3: value is equal to the limit value

Limit evaluation

The limit evaluation assumes a signed representation. The conversion to the desired representation (index 0x80n0:02) only takes place after the limit evaluation.

Swap Limit (index 0x80n0:0E)

The limit function can be inverted by SwapLimitBits in index 0x80n0:0E.

Setting SwapLimitBits in index 0x80n0:0E	Output value (2 bits) in index 0x60n0:03 for limit 1 in index 0x60n0:05 for limit 2
FALSE (default setting)	0: not active 1: Value < limit value 2: Value > limit value 3: Value = limit value
TRUE	0: not active 1: Value > limit value 2: Value < limit value 3: Value = limit value

The Swap limit function („Swap limit bits“, CoE object 0x80n0:0E) is available according to the table below

Terminal	Swap limit function from
EL300x	Firmware 05, Rev. EL300x-000-0018
EL301x, EL302x	Firmware 01, Rev. EL301x-0000-0016 Firmware 01, Rev. EL302x-0000-0016
EL3041, EL3042, EL3042-0017	Firmware 05, Rev. EL3041-0000-0017 Firmware 05, Rev. EL3042-xxxx-0017
EL3044, EL3048	Firmware 06, Rev. EL3044-000-0017 Firmware 06, Rev. EL3048-000-0017
EL3051, EL3052	Firmware 05, Rev. EL3051-000-0017 Firmware 05, Rev. EL3052-000-0017
EL3054, EL3058	Firmware 06, Rev. EL3054-000-0017 Firmware 06, Rev. EL3058-000-0017
EL3061, EL3062	Firmware 04, Rev. EL3061-000-0017 Firmware 04, Rev. EL3061-000-0017
EL3064, EL3068	Firmware 06, Rev. EL3064-000-0017 Firmware 06, Rev. EL3068-000-0017
EL3072, EL3074	Firmware 02, Rev. EL3072-0000-0016 Firmware 02, Rev. EL3074-0000-0016

Example for EL3062:

Channel 1; Limit 1 and Limit 2 enabled, Limit 1 = 2.8 V, Limit 2 = 7.4 V, representation: signed integer

Specification of the limit values:

for limit 1 in index 0x8000:13: (2.8 V / 10 V) x 2¹⁶ / 2 - 1 = 9,174_dec
for limit 2 in index 0x8000:14: (7.4 V / 10 V) x 2¹⁶ / 2 - 1 = 24,247_dec

Output of the limit value evaluation

Input channel 1	Index 0x6000:03	Index 0x6000:05
1.8 V	0x01_hex, (Limit 1, limit value undershot)	0x01_hex, (Limit 2, limit value undershot)
2.8 V	0x03_hex, (Limit 1, limit value reached)	0x01_hex, (Limit 2, limit value undershot)
4.2 V	0x02_hex, (Limit 1, limit value exceeded)	0x01_hex, (Limit 2, limit value undershot)
8.5 V	0x02_hex, (Limit 1, limit value exceeded)	0x02_hex, (Limit 2, limit value exceeded)

Linking in the PLC with 2-bit values

The limit information consists of 2 bits. Limitn can be linked to the PLC or a task in the System Manager.

PLC:
IEC61131-PLC contains no 2-bit data type that can be linked with this process data directly. For transferring the limit information, define an input byte (e.g. see Fig. Input byte definition) and link the limit to the VariableSizeMismatch dialog, as described in section Note about the 1-byte status of earlier EtherCAT Terminals.

Additional task
2-bit variables can be created in the System Manager.