Example 2: Writing to an user register

Example 2: Writing to an user register 1:

Code word

In normal mode all user registers are read-only with the exception of Register 31. In order to deactivate this write protection you must write the code word (0x1235) into Register 31. If a value other than 0x1235 is written into Register 31, write protection is reactivated. Please note that changes to a register only become effective after restarting the terminal (power-off/power-on).

I. Write the code word (0x1235) into register 31.

Output Data

Byte 0: Control byte

Byte 1: DataOUT1, high byte

Byte 2: DataOUT1, low byte

0xDF (1101 1111bin)

0x12

0x35

Explanation:

Input Data (answer of the Bus Terminal)

Byte 0: Status byte

Byte 1: DataIN1, high byte

Byte 2: DataIN1, low byte

0x9F (1001 1111bin)

0xXX

0xXX

Explanation:

II. Read Register 31 (check the set code word)

Output Data

Byte 0: Control byte

Byte 1: DataOUT1, high byte

Byte 2: DataOUT1, low byte

0x9F (1001 1111bin)

0xXX

0xXX

Explanation:

Input Data (answer of the Bus Terminal)

Byte 0: Status byte

Byte 1: DataIN1, high byte

Byte 2: DataIN1, low byte

0x9F (1001 1111bin)

0x12

0x35

Explanation:

III. Write to Register 32 (change contents of the feature register)

Output data

Byte 0: Control byte

Byte 1: DataIN1, high byte

Byte 2: DataIN1, low byte

0xE0 (1110 0000bin)

0x00

0x02

Explanation:

CAUTION

Observe the register description!

The value of 0x0002 given here is just an example!
The bits of the feature register change the properties of the terminal and have a different meaning, depending on the type of terminal. Refer to the description of the feature register of your terminal (chapter Register description) regarding the meaning of the individual bits before changing the values.

Input data (response from the Bus Terminal)

Byte 0: Status byte

Byte 1: DataIN1, high byte

Byte 2: DataIN1, low byte

0xA0 (1010 0000bin)

0xXX

0xXX

Explanation:

IV. Read register 32 (check changed feature register)

Output Data

Byte 0: Control byte

Byte 1: DataOUT1, high byte

Byte 2: DataOUT1, low byte

0xA0 (1010 0000bin)

0xXX

0xXX

Explanation:

Input Data (answer of the Bus Terminal)

Byte 0: Status byte

Byte 1: DataIN1, high byte

Byte 2: DataIN1, low byte

0xA0 (1010 0000bin)

0x00

0x02

Explanation:

V. Write register 31 (reset code word)

Output Data

Byte 0: Control byte

Byte 1: DataOUT1, high byte

Byte 2: DataOUT1, low byte

0xDF (1101 1111bin)

0x00

0x00

Explanation:

Input Data (answer of the Bus Terminal)

Byte 0: Status byte

Byte 1: DataIN1, high byte

Byte 2: DataIN1, low byte

0x9F (1001 1111bin)

0xXX

0xXX

Explanation: