4. Configuration
77
Serial Interfaces Configuration
COM 1
The COM 1 communication interface is composed by a DB9 female connector for RS-232C and RS-
485 (non-isolated) interfaces. It allows peer to peer or network communication in open protocols,
MODBUS RTU slave or MODBUS RTU master. The network communication is performed through
a converter.
Table 4-19 presents the parameters that must be configured for the proper functioning of the
application.
When using the MODBUS Master/Slave protocol, some of these parameters (such as Serial Mode,
Data Bits, RX Threshold and Serial Events) are adjusted automatically by MasterTool so the protocol
works properly.
Configurations
Description
Default
Options
Serial type
Serial channel type
configuration
RS-232C
RS-232C or RS-485
Baud Rate
Serial communication port
speed
115200
600, 1200, 1800, 2400,
4800, 9600, 19200,
38400, 57600, 115200
bps
Parity
Serial port parity configuration
None
Odd
Even
Parity Always One
Parity Always Zero
No Parity
Data bits
Sets the number of data bits
in each character of the serial
communication
8
5, 6, 7 and 8
Stop bits
Sets the stop bits of the serial
port
1
1, 1.5 and 2
Serial mode
Sets the serial port operation
mode
Normal mode
- Extended Mode:
Extended operation
mode of the serial
communication that
delivers information
regarding the received
data frame.
- Normal Mode: Normal
operation mode of the
serial communication.
Table 4-19. COM 1 Settings
Note:
Extended Mode:
In this operation mode, the CPU provides information regarding the received data
frame. The available information is:
One byte for the received data (RX_CHAR : BYTE): Store five, six, seven or eight bits from the
received data, depending on the serial communication configuration.
One byte for the signal errors (RX_ERROR : BYTE): Has the following format:
Bit 0: 0 - the character in bits 0 to 7 is valid. 1 - the character in bits 0 to 7 is not valid (or it
cannot be valid), due to problems indicated in bits 10 to 15
Bit 1: Not used
Bit 2: Not used
Bit 3: UART interruption error. The serial input remained in logic 0 (parity always zero) for a
time greater than a character (start bit + data bit + parity bit + stop bit)
Bit 4: UART frame error. The logic 0 (parity always zero) was read when the first stop bit was
expected and it should be logic 1 (parity always one)