Group 52: Standard Modbus - ABB ACS 400 User Manual

Group 52: Standard Modbus

The ACS 400 can be connected to a Modbus fieldbus system. Parameters of this group are used to
set up station number, communication speed and parity. Parameters 5206 - 5215 are diagnostic
counters that can be used to debug the fieldbus system. Refer to "Standard Serial Communication"
on page 95 for more information.
Code Description
5201 STATION ID
Sets the slave number for the ACS 400 in Modbus network.
Range: 1 - 247
Note! Modifications take effect only on the next power up.
5202 COM SPEED
Defines the communication speed of the ACS 400 in bits per second (bps).
3 = 300 bps
6 = 600 bps
12 = 1200 bps
24 = 2400 bps
Note! Modifications take effect only on the next power-up.
5203 PARITY
Defines the parity to be used with the Modbus communication. Parameter also defines the number of stop
bits. With Modbus communication, the number of stop bits is 2 with no parity bit, and 1 with even or odd
parity.
0 =
NONE
1 =
EVEN
2 =
ODD
Note! Modifications take effect only on the next power-up.
5206
BAD MESSAGES
This diagnostics counter increases by one every time the ACS 400 finds any kind of communication error.
During normal operation, this counter hardly ever increases.
5207
GOOD MESSAGES
This diagnostics counter increases by one every time a valid Modbus message has been received by the
ACS 140. During normal operation, this counter is increasing constantly.
5208
BUFFER OVERRUNS
Longest possible message length for the ACS 400 is 32 bytes. If a message exceeding 32 bytes is received,
this diagnostic counter increases by one every time a character is received and cannot be placed in the
buffer.
5209
FRAME ERRORS
This diagnostic counter increases by one every time when a character with a framing error is received from
the bus.
• Communication speed settings of the devices connected in the bus differ.
• Ambient noise levels may be too high.
5210
PARITY ERRORS
This diagnostic counter increases by one every time when a character with a parity error is received from
the bus.
• Parity settings of the devices connected in the bus differ.
• Ambient noise levels may be too high.
92
48 = 4800 bps
96 = 9600 bps
192 = 19200 bps
ACS 400 User's Manual