ABB FSCA-01 Manual page 16

16
5 PARITY
Defines the use of parity and stop bit(s) and the data length. The
same settings must be used in all on-line stations.
(0) 8 NONE 1
(1) 8 NONE 2
(2) 8 EVEN 1
(3) 8 ODD 1
6 MODBUS TIMEOUT
The Modbus protocol does not specify a timeout mechanism for
the application layer. ABB Drives and the FSCA-01 RS-485
Adapter Module provide a Modbus timeout method as it may be
desired for drive control.
The timeout is
MODBUS TIMEOUT value * 100 milliseconds.
For example, a MODBUS TIMEOUT value of 22 would result in a
timeout of
22 * 100 milliseconds = 2.2 seconds
TIMEOUT MODE is used to define which Modbus register
accesses reset the timeout counter. See configuration parameters
group A, parameter 7 for defining the TIMEOUT MODE.
When a Modbus timeout occurs, the adapter module signals the
drive that communication with the master has been lost. The drive
configuration determines how it responds. For example, if you
configure the MODBUS TIMEOUT as 250 ms and the drive is
configured to fault on a communication failure with a delay of 500
ms, then the drive faults 750 ms after the communication is lost.
Drive configuration
No parity bit, one stop bit, 8 data bits
No parity bit, two stop bits, 8 data bits
Even parity indication bit, one stop bit, 8 data bits
Odd parity indication bit, one stop bit, 8 data bits