Baud Rates And Mapping Tables - Siemens SINAMICS G120 CU230P-2 HVAC Operating Instructions Manual

Configuring the fieldbus
6.2 Communication via RS485
6.2.3.4

Baud rates and mapping tables

Permissible baud rates and telegram delay
The Modbus RTU telegram requires a pause for the following cases:
● Start detection
● Between the individual frames
● End detection
Minimum duration: Processing time for 3.5 bytes (can be set via p2024[2]).
A character delay time is also permitted between the individual bytes of a frame. Maximum
duration: Processing time for 1.5 bytes (can be set via p2024[1]).
Table 6- 29
Baud rate in bit/s (p2020)
4800
9600
19200 (factory setting)
38400
57600
76800
93750
115200
187500
Note
The factory setting for p2024[1] and p2024[2] is 0. The particular values are pre-assigned
depending on the protocol selection (p2030) or the baud rate.
Modbus register and Control Unit parameters
Since the Modbus protocol can only handle register or bit numbers for addressing the
memory, assignment to the appropriate control words, status words and parameters is
performed on the slave side.
The converter supports the following addressing ranges:
Addressing range
40001 ... 40065
40100 ... 40522
136
Baud rates, transmission times, and delays
Transmission time per
character (11 bits)
2.292 ms
1.146 ms
0.573 ms
0.286 ms
0.191 ms
0.143 ms
0.117 ms
0.095 ms
0.059 ms
Remark
Compatible with Micromaster MM436
Frequency inverters with Control Units CU230P-2 HVAC, CU230P-2 DP, CU230P-2 CAN
Minimum pause
between two
telegrams (p2024[2])
≥ 8.021 ms
≥ 4.010 ms
≥ 1.75 ms
≥ 1.75 ms
≥ 1.75 ms
≥ 1.75 ms
≥ 1.75 ms
≥ 1.75 ms
≥ 1.75 ms
Operating Instructions, 01/2011, FW 4.4, A5E02430659B AD
Maximum pause
between two bytes
(p2024[1])
≤ 3.438 ms
≤ 1.719 ms
≤ 0.859 ms
≤ 0.75 ms
≤ 0.556 ms
≤ 0.417 ms
≤ 0.341 ms
≤ 0.278 ms
≤ 0.171 ms