therefore users will need to be more aware of the settings. Some equipment parts (RS-485 converters
or modules) provide terminating, pull-high, pull-low resistors, and VBus settings. Please refer to the
corresponding operation manuals before installation and connection. For VBus, the standard is 5 V,
for pull-high and pull-low resistors, 1 K
, and for terminating resistors, 120 K
.
3.
Without repeaters, the RS-485 network cannot exceed a maximum of 32 nodes. The maximum
transmission communication distance for RS-485 is up to 1200 meters. For long distance transmission,
it is recommended to use cables that are specifically design for RS-485.
4.
When communicating, all equipment within the network should be consistently kept in the same
transfer mode, baud rate, and parity. All devices must be under different addresses to prevent conflicts
within the network communications.
5.
The transmitter’s Modbus command can only access 50 registers. Abnormal information will be
returned if the maximum length is exceeded.
6.
The idle time in which a slave instrument responds to a master machine is different according to
each model. Generally, the time needed should be longer than 0.5 seconds (some models may
require a longer waiting-responding time, please note if the operation manual specifies).
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