4RF Limited SRN0400025A ユーザーズマニュアル
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Aprisa SR User Manual
USB RS-232 Serial Port
The Aprisa SR USB host port is predominantly used for software upgrade and diagnostic reporting.
However, it can also be used to provide an additional RS-232 DCE serial port for customer traffic.
However, it can also be used to provide an additional RS-232 DCE serial port for customer traffic.
This is accomplished with a USB to RS-232 serial converter cable. This plugs into the USB host port
connector and can be terminated with the required customer connector.
This additional RS-232 serial port is enabled with the SuperVisor mode setting in Serial Port Settings (see
‘Serial > Port Setup’ on page 95).
‘Serial > Port Setup’ on page 95).
USB RS-232 operation
The USB serial converter buffers the received data frames into 64 byte blocks separated by a small inter-
frame gap.
frame gap.
For the majority of applications, this fragmentation of egress frames is not an issue. However, there are
some applications that may be sensitive to the inter-frame gap, therefore, these applications need
consideration.
some applications that may be sensitive to the inter-frame gap, therefore, these applications need
consideration.
A 5 ms inter-frame is recommended for the applications that are sensitive to inter-frame gap timings.
On a USB RS-232 port, Modbus RTU can operate up to 9600 baud with all packet sizes and up to 115200 if
the packet size is less than 64 bytes. The standard RS-232 port is fully compatible with Modbus RTU at all
baud rates.
the packet size is less than 64 bytes. The standard RS-232 port is fully compatible with Modbus RTU at all
baud rates.
Cabling Options
The following converter cables are available as Aprisa SR accessories to provide the customer interface:
1. USB Converter to 1.6 metre multi-strand cable 6 wire for termination of customer connector
Part Number
Part Number
APSA-IFCA-USB-MS-16
4RF SR Acc, Cable, Interface, USB Converter, Multi-strand, 1.6m
2. USB converter to RJ45 female kit for USB to RS-232 DCE conversion. The RJ45 is mounted in a strain
relief retention bracket.
Part Number
Part Number
APSA-KFCA-USB-45-MF-04
4RF SR Acc, Kit, Interface, USB Converter, RJ45, Female, 0.4m
3. USB converter to DB9 female kit for USB to RS-232 DCE conversion. The DB9 is mounted in a strain
relief retention bracket.
Part Number
Part Number
APSA-KFCA-USB-D9-MF-04
4RF SR Acc, Kit, Interface, USB Converter, DB9, Female, 0.4m