Simon Collings - RS-232 Interfacing for Receiver Control

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RS-232 Control of the AOR SDU-5500

Interface Unit: None (connection is direct)

Standard Connections Used: TXD, RXD, GND, RTS, CTS

Flow Control: Software

Type of RS-232 Command Set: ASCII

Data Parameters: 9600 baud; 2 stop bits; no parity

Overview of SDU-5500 Interface

Note: This description assumes that you are using an SDU-5500 with firmware release V1.010. As the firmware is field updatable, if you do not have this version installed you can update by contacting your AOR dealer.

The SDU-5500 is a spectrum display unit which can be used with the AR-5000, other AOR receivers and also certain Icom radios. It is connected to the RS-232 interface of your radio while your PC is connected to the SDU-5500. The RS-232 command set supports operation of the SDU-5500 (and therefore indirect control of the companion radio) and also direct control of an AR-5000 only using a * prefix to AR-5000 command strings. The SDU-5500 is functionally similar to the older SDU-5000 but suppportes a wider range of functions.

The RS-232 command interface is different to both the SDU-5000 and the AOR radios. It uses a unique command format incorporating read/write action, command category, type and parameters. Each RS-232 command is built from these elements. There are four command categories:

S	Spectrum analysis for controlling the analysis features of the SDU-5500
V	Visual commands for altering the display on the SDU-5500
U	User unterface for mode and receiver operations
I	Information (used only in production testing)

All commands respond with <CR> if processed correctly or ?<CR> if the SDU-5500 failed to process the command because of an error.

RS-232 connector pinout

SDU-5500	Function	PC 25-way D-type	PC 9-way D-type
5	Frame & signal ground	7	5
3	TX data	2	3
2	RX data	3	2
7	RTS	4	7
8	CTS	5	8

SDU-5500 Command Set

Function

Read/Write

Category

Type

Parameter

Comments

Centre frequency

Spectrum Analysis
(S)

Value n.n in MHz
(Note: range determined
by companion receiver
capability)

To set:
WSCFn.n<CR>

To read:
RSCF<CR>
Responds with SCFn.n<CR>

Span

R/W

Value n in kHz
Range: 1-10000

To set:
WSSPn<CR>

To read:
RSSP<CR>
Responds with SSPn<CR>

RBW

R/W

1	5 kHz
2	30 kHz

To set:
WSBWn<CR>

To read:
RSBW<CR>
Responds with SBWn<CR>

Gain

R/W

1	Low
2	High

To set:
WSGNn<CR>

To read:
RSGN<CR>
Responds with SSGn<CR>

Cursor

R/W

1	MKR
2	PEAK
3	CPEAK

To set:
WSCMn<CR>

To read:
RSCM<CR>
Responds with SCMn<CR>

Data mode

R/W

1	Normal
2	AVR
3	MAX

To set:
WSDMn<CR>

To read:
RSDM<CR>
Responds with SDMn<CR>

AVR sample

R/W

Range: 2-32

To set:
WSAVn<CR>

To read:
RSAV<CR>
Responds with SAVn<CR>

Plot mode

R/W

Visual command
(V)

1	Paint
2	Outline

To set:
WSPMn<CR>

To read:
RSPM<CR>
Responds with VPMn<CR>

FDIR

R/W

1	Normal
2	Reverse

To set:
WVDDn<CR>

To read:
RVDD<CR>
Responds with VDDn<CR>

LCD contrast

R/W

Range: 0-160

To set:
WVCLn<CR>

To read:
RVCL<CR>
Responds with VCLn<CR>

LCD display mode

R/W

1	Normal
2	Reverse

To set:
WVRVn<CR>

To read:
RVRV<CR>
Responds with VRVn<CR>

Send Visual Image

N/A

To read:
RVIM<CR>
Responds with a bit image of the LCD display sent as ASCII represented hex characters starting from the top left hand corner and extending to the bottom right. The image is 304x128 pixels in size. An X is sent to indicate end of image data.

Example:
VIM00000000...F01FFFFFFFFFF0000X

Receive mode

R/W

User Interface
(U)

1	WFM
2	NFM
3	AM
4	LSB
5	USB
6	CW
7	AUTO

To set:
WUMDn<CR>

To read:
RUMD<CR>
Responds with UMDn<CR>

Attenuator

R/W

1	On
2	Off

To set:
WUATn<CR>

To read:
RUAT<CR>
Responds with UATn<CR>

Step size

R/W

Value n.n in kHz
(Note: range determined
by companion receiver
capability)

To set:
WUSTn.n<CR>

To read:
RUST<CR>
Responds with USTn.n<CR>

Companion RX

R/W

1	AR5000
2	AR3000A
3	IC-R7100
4	IC-R8500
5	IC-R9000
6	Other

To set:
WURXn<CR>

To read:
RURX<CR>
Responds with URXn<CR>

MK-CF

N/A

To set:
WUMC<CR>

Step up

N/A

To set:
WUSU<CR>

Step down

N/A

To set:
WUSD<CR>

Page up

N/A

To set:
WUPU<CR>

Page down

N/A

To set:
WUPD<CR>

LCD MKR step

1	Down
2	Up

To set:
WUDSn<CR>

Monitor mode

R/W

1	SPECT
2	STRES
3	CHANL

To set:
WUOMn<CR>

Note: when using CHANL (n=3), the range must first be specified

To read:
RUOM<CR>
Responds with UOMn<CR>

CHANL mode

R/W

Start (MHz)
Step (kHz)
End (MHz)

To set:
WUCSn.n n.n n.n<CR>

To read:
RUCS<CR>
UCSn.n n.n n.n

Emit Beep

1	Low
2	High

To set:
WUBEn<CR>

MK-RF
(CHANL mode)

N/A

To set:
WUMR<CR>

CH Mode MKER

R/W

Value n.n in MHz
(Note: range determined
by companion receiver
capability)

To set:
WURFn.n<CR>

To read:
RURF<CR>
Responds with URFn.n<CR>

Graphic download

Information
(I)

N/A

To read:
RIGD<CR>
Responds with slow speed video data comprising 304 lines containing frequency and level data as formatted ASCII text.

Example:
IGD
/
F131.22829,L-76
F131.23158,L-70
F131.23487,L-75
...
F132.22500,L-72
/

Cursor download

N/A

To read:
RICD<CR>
Responds with current cursor frequency and level

Example:
f131.72500,l-71

Note: the use of lower case instead of the usual upper case for some reason

High speed data
download

N/A

To read:
RIFD<CR>
Responds with high speed video data. This is a streamlined version of the slow speed video data obtained with RIGD. The reduction in the amount of text sent improves the speed of transfer.

The format is a single line of 304 video samples reported as ASCII text values (character values: 20H - 70H). This corresponds to a signal level range of -90dbm to -40dbm or -60 to -10dbm depending on gain setting (high/low).

Example:

IFD<CR>
(304 ASCII characters in the range <space> to 'R' or '>' to 'p' depending on gain setting)

Firmware version

N/A

To Read:
RIVE<CR>
Responds with: IVE Ver. n.nnn<CR>

AR-5000 direct commands

If you are using an AR-5000 as companion radio, it is possible to send command strings to this radio via the SDU-5500 by prefixing with an asterisk (*). Transfer to the AR-5000 takes place only after the SDU-5500 has completed its latest command sequence, at which point it will wait for a response from the radio and report it back over the RS-232 link.

Example:

*MD<CR><LF>

will produce a response of the form

*AU0 MD3<CR><LF>