NORD Drivesystems BU0050 - Manual (Page 42)

NORD USS and Modbus RTU Manual
42 Subject to technical amendments BU 0050 GB-3111
1.5.4.3 Parameter value (PWE)
According to the type of the PPO or parameter, transfer of the parameter value (PWE) is always as a word
(16 Bit) or double word (32 Bit) Only one parameter value can be transferred in a telegram.
A 32 bit parameter value comprises PWE1 (high value word) and PWE2 (low value word, 4th word).
A 16 Bit parameter value for PPO1 and PPO2 is transferred in PWE2. For negative values the High word
must be set to FFFF hex.
Note: 32-Bit parameter values are only used with the POSICON option. All the relevant parameters are
described in the POSICON supplementary manual.
The parameter value is transferred as an integer value. For parameters with resolutions 0.1 or 0.01 the
parameter value must be multiplied by the inverse of the resolution.
Example: A start-up time of 99.99 seconds is to be set:
99.99s

99,99 * 1/0.01 = 99.99 * 100 = 9999. Therefore the value 9999
dec
= 270F
hex
must be transferred.
1.5.4.4 Master Function Output
With a setting in parameter P503, the inverter control signals (digital and/or analog) which are to be output as
a bradcast telegram (type PPO3/PPO4) in USS protocol format via the RS 485 interface can be selected.
The control source is still selected in P509. The transfer intervals depend on the USS baud rate which is set:
Baud rate Interval
4800 Baud 100 ms
9600 Baud 50 ms
19200 Baud 25 ms
38400 Baud 15 ms