Stop Bits (40137); Data Bits (40138); Parity Bit (40139) - iSMA CONTROLLI iSMA-B-MG-IP User Manual

iSMA-B-MG-IP User Manual
Baud rate = Register value • 10

5.3.10 Stop Bits (40137)

Number of stop bits is determined on the basis of this register in accordance with the
following table:
Value
1 (default)
2
256
Bit no. 8 activates RS485 biasing resistors in order to pull up voltage on the RS485 bus. If
the bit no. 8 is true (bit 8 = 1), then RS485 biasing resistors are activated. The function is
only available in MG-IP devices with a hardware version 2.0 or higher.
The biasing resistors are useful in case the iSMA modules are connected with a third part
devices with the same RS485 bus and communication errors appears on the network.
WARNING! Only one single device in the network can have biasing resistors activated!

5.3.11 Data Bits (40138)

Number of data bits transmitted in a single byte is determined according to the following
table:
Value
7
8 (default)

5.3.12 Parity Bit (40139)

Each byte of data being transferred may have additional protection as a parity bit added
before stop bit (bits).
The method of calculating parity bit determines the table below:
Figure 9. Modbus frame
Table 10. Data bits
www.ismacontrolli.com
No. of Stop Bits
1
2
RS485 biasing*
Table 9.
No. of Data Bits
7
8
DMP260en | 1st Issue rev. 6 | 05/2022 page 17 of 29