User guide

83
9 RS485 Communication
9.5 Motor status byte
The bits of the motor status byte have the following meaning:
Bit Meaning Comment
0 bUebertemperatur 1 = Drive detects overtemperature
1 bMotorAktiv 1 = Drive is active
2 bUeberspannung 1 = drive detects overvoltage
3 bUnterspannung 1 = drive detects undervoltage
4 bHWFehler 1 = drive detects hardware fault
5 bUeberstrom 1 = drive detects overcurrent
6 bQuittErforderlich 1 = drive needs an acknowledgement
7 bDBereit 1 = drive is ready
9.6 Checksum
The checksum is calculated as follows:
• All bytes including the start byte are added together.
– As, in special cases, the sum can be 0 and an empty telegram would be interpreted as “Run command speed with target speed = 0 and
maximum current = 0”, the sum is disjuncted with 0 x 55. In this way the special case is detected.
Formula: Checksum = (sum (Byte0..last_Byte)) || 0x55
9.7 “Speed” run command
The “speed” run command described here initiates speed-controlled operation, if the setpoint selector of the drive has been used to activate
“RS485 speed input”.
NOTE
In the case of static operation with a speed, the command must be sent cyclically every 2 sec. at the latest, as otherwise
the drive detects a bus interruption and specifies an error speed (parameter 0x16).
9.7.1 Requirements
RS485 Char Use Value / Comment
1 Start byte COM_CRX_FAHRBEFEHL_DREHZAHL
2 Address byte Bus address
3 Target speed Hi rpm, -32768…32767
4 Target speed Lo
5 Maximum current Hi
6 Maximum current Lo 0-100 %
7 Checksum