FOB Fast – Analog tab

General columns in the signal table

Only for normal mode and connection modes using integer data:

Min

Lower limit of measuring range

The analog voltage standard level of -10 V is assigned to a physical variable of -10 °C, for example. The value can be entered directly or set with two-point scaling.

Max

Upper limit of measuring range

The technological upper limit of the measuring range is to be entered here.

The analog voltage standard level of +10 V is assigned to a physical variable of 43 °C, for example. The value can be entered directly or set with two-point scaling.

For advanced mode or with connection modes using real data:

Gain and offset

The values for gain and offset describe a linear characteristic curve for scaling. If incoming values are given in physical units, gain and offset can be ignored, i.e. set gain = 1 and offset = 0. When using physical values, gain and offset can be ignored, i.e. set gain = 1 and offset = 0.

However, control applications of the connected automation systems often use normalized values for calculation; so, analog values only range, for example, between 0 and 1 or -1 and +1. In order to get a correct scale for display in terms of physical units, a scaling factor needs to be specified. This factor can be evaluated from the gain and offset parameters.

Gain and offset can be entered directly or set by means of the two-point scaling with two pairs of applicable values.

You can open the dialog for two-point scaling with a click on the small button in the fields "Gain" or "Offset." (Cursor must be in the fields to see the button.)

For advanced mode only:

Address

In this additional column (together with the "Data type" column), the user can specify the address, i.e. the byte-offset of the different channels in the Fob telegram. The offset can be entered as hexadecimal or decimal values by selecting the appropriate option from the context menu. Default setting is 0x40 for analog values and 0xC0 for digital values. If you want to change the values for an entire column, you just need to change the first value and then click on the column header. Based on the address offset of the first signal, all other values below will be automatically set according to data and value type:

• Analog signals in FLOAT format: in 4 byte steps

• Analog signals in INT16 format: in 2 byte steps

• Analog signals in BYTE format: in 1 byte steps

• Digital values in 32-bit groups: increment of the bit no. by 1 up to 31. Then increment of the address by 4.

For the digital signals, you may use a DINT to transmit 32 single bits. You can unpack these by specifying the address and bit no. Except for the first one, it is not necessary to enter a new address for the bits in a DINT.

Data type

In each field of this column, you can select the data type in use.

Click in a table cell and open the drop-down list.

Available for selection are:

As the set memory addresses change according to the data type, it might be necessary to adjust the addresses afterwards.