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 | Output value (2 bits) |
|---|---|
FALSE (default setting) |
|
TRUE |
|
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, | Firmware 01, Rev. EL301x-0000-0016 |
EL3041, | Firmware 05, Rev. EL3041-0000-0017 |
EL3044, | Firmware 06, Rev. EL3044-000-0017 |
EL3051, | Firmware 05, Rev. EL3051-000-0017 |
EL3054, | Firmware 06, Rev. EL3054-000-0017 |
EL3061, | Firmware 04, Rev. EL3061-000-0017 |
EL3064, | Firmware 06, Rev. EL3064-000-0017 |
EL3072, | Firmware 02, Rev. EL3072-0000-0016 |
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 = 9,174dec
- for limit 2 in index 0x8000:14: (7.4 V / 10 V) x 216 / 2 - 1 = 24,247dec
Output of the limit value evaluation
Input channel 1 | Index 0x6000:03 | Index 0x6000:05 |
|---|---|---|
1.8 V | 0x01hex, (Limit 1, limit value undershot) | 0x01hex, (Limit 2, limit value undershot) |
2.8 V | 0x03hex, (Limit 1, limit value reached) | 0x01hex, (Limit 2, limit value undershot) |
4.2 V | 0x02hex, (Limit 1, limit value exceeded) | 0x01hex, (Limit 2, limit value undershot) |
8.5 V | 0x02hex, (Limit 1, limit value exceeded) | 0x02hex, (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.
Fig.228: Input byte definition
Fig.229: Linking of 2-bit variable to additional task