APS 6RL Series, Руководство по эксплуатации

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6RL SERIES OPERATION MANUAL
SECTION 7: REMOTE PROGRAMMING
Entire Contents Copyright

2018 by Adaptive Power Systems, Inc. (APS) • All Rights Reserved • No reproduction without written authorization from APS.
6RL Series Regenerative DC Load Operation Manual Page 116 of 204
Series Typical response time
DCS Series
6RL Series
SCPI: via USB <5 ms
(2
, via Ethernet <10 ms
(1
ModBus: via USB <5 ms
(2
, via Ethernet <10 ms
(1
CAN/CANopen: ≈2 ms
1) Acquired from a measurement of 200,000 command cycles of method 1 via interfaces OPT-ETH1P (Ethernet) and OPT-MBUS1
(standard Ethernet port 5025)
2) Acquired from a measurement of 200,000 command cycles of method 1 via the virtual COM port of the USB driver
Note: The response time of both, USB and Ethernet, may vary depending on the
communications module firmware version installed on your unit and can better or
worse than listed here.
7.2.6.3 Message Timing
The minimum time between two messages, as listed below, primarily depends on the typical
response time as listed in the previous section.
Series Minimum time between two messages Recommended time between two messages
DCS Series
6RL Series
USB / CAN / CANopen: 10 ms
Ethernet: 15 ms
USB / CAN / CANopen: 20 ms
Ethernet: 30 ms
7.3 Communications Protocols Overview
There are two supported protocols: ModBus RTU and SCPI. Both can be used via RS232,
USB and most of the Ethernet based interfaces. Exceptions are those related to dedicated
standards such as CAN, CANopen, Profibus, Profinet or EtherCAT.
When using a ModBus TCP interface module and depending on the addressed port, there is
a distinction between ModBus RTU and ModBus TCP with respect to the message format.
The reserved and dedicated port 502 supports only ModBus TCP frames, while all other
ports would only support frames with a ModBus RTU or SCPI message.
Note: With option GPIB (GPIB+USB+Analog) installed, only SCPI can be used via GPIB. With
USB, ModBus RTU is supported as well.
The integrated USB-B device port located on the rear panel of the unit can be used for both
protocols. Which protocol to use is determined by the unit by the first byte of a message,
except when using the ModBus TCP protocol. According to the ModBus TCP standard, a six-
byte MBAP header is added to any ModBus format message and is usually sent using the
dedicated port 502. A SCPI or ModBus RTU message sent to this port would cause a
communication error.
Depending on the selection of the interface and the protocol you are going to use, a
different section of this manual will be relevant.
Some interface standards, such as Profibus/Profinet, require a different protocol format and
transmission scheme towards a bus or network and the interface modules then act as
translators. In this case, the user cannot use any of the default protocols, but is tied to the
standard given by the interface specifications.