Transcript
CONNECTING an ICOM RADIO to a PC 1. INTRODUCTION This document is intended to provide insight and understanding on how an ICOM radio can be connected to a PC running common Logging and Operating (SSB, Digital) software. Connectivity is demonstrated to show how communications between the Radio and PC can be implemented. Examples are provided that have been installed and run on an IC-756 and now on an IC 7700 radio with a basic Win 7 PC. Software applications currently running are,
N1MM_Logger+, WriteLog V11.24, MMTTY V1.68A, FLDIGI V3.22.05
Note: Simple interfaces are provided in Figures 1 through 5 and are home-made. You do not have to make these items as one can buy complete interface products, but it may be informative to see what these do, and how. 2. COMMUNICATIONS There are two distinct interfaces to deal with: CI-V Radio Data information, and Radio Control signaling to the Accessory socket. CI-V is the data interface. It is Icom’s proprietary Computer Interface – Revision V (5) software.
It is a bi-directional, digital interface that communicates the status of controllable features of the radio to the PC, and the PC to the Radio. For applications mentioned above, these would typically be Frequency, Mode, Band. CI-V can also command PTT.
The Accessory (ACC1 or ACC) socket is a hardware interface.
It is not a communication interface. It is a Rig Control and Audio input/output interface. Main control functions are PTT using Send, and FSK keying using RTTY. It has TX audio input on MOD and RX audio output on AF. For CW keying, the KEY jack on the rear panel is used.
3. RS-232
RS-232 is a communications standard allowing equipment to be managed by a computer. Communications is carried on through a “Serial” port equipped on PC’s. The RS-232 serial port is the COM port on the computer. It sends and receives data, one bit at a time, over one wire. The connecting cable typically has 9 wires, with designated functions operating in parallel. They can send and receive data at the same time. The “signal” consists of a positive and negative voltage referenced to ground to indicate a 1 or a 0 “bit”.
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CONNECTING an ICOM RADIO to a PC
Example: the digital “word” in the above diagram is “8” bits long. It is 00101101. The voltage on the RS-232 cable toggles symmetrically anywhere between a minimum of 5 and 15V with respect to signal ground.
4. DB-9 Connector
For connecting to COM ports, RS-232 cables use a connector having 9 pins. There are Male and Female versions. COM ports on PC’s are DB-9 Male.
Pins are functionally designated. Those listed here most often appear in software setups. o o o o o
RXD, pin 2 typically receives data in to PC. Used by CI-V. TXD, pin 3, typically transmits data out of the PC. Used by CI-V. DTR, pin 4, typically transmits commands. GND, pin 5 is signal ground. RTS, pin 7 typically transmits commands.
Commands are set in the software setup and control operations such as PTT, FSK, CW, or other. The above are NOT always assigned as listed. Software designers can reassign functionality. It is not necessarily consistent across platforms.
5. Converters
RS-232 toggles between +V and –V. CI-V uses a signal between +V and ground. Command signals for CW, FSK, PTT, are usually ground-to-activate & open-circuit for “off”. Signal level-wise, they are incompatible with each other. Level converters are required to shift signal levels between the COM port and the CI-V and the Accessory Inputs. The CI-V Level Converter is used exclusively for the CI-V interface input/output. The RS-232 Interface Converter is used exclusively for the Accessory socket inputs.
6. COM Ports
COM ports require setup. Unless there is a special requirement, these settings typically work. o o o o o
Bits per Second Data Bits Parity Stop Bits Flow Control
19200, or at least equal to or greater than required by S/W 8 None 1 None
Pay attention to the software being used as to how it wants to be configured during set up.
7. PC / Software
It is recommended that each software application have its own COM Port to avoid conflicts. Expect each application to have a setup specific to its needs. Sometimes a port can be shared, but only one application can be run at a time. 2
CONNECTING an ICOM RADIO to a PC 8. Assess COM port Status on PC (Win 7)
Start > Control Panel > System and Security > System > Device Manager. Expand Ports COM & LPT. A list of installed COM ports is shown. This does not tell you which COM ports are available. You have to know. Typically COM 1 is not available. The PC may not even have a hardware equipped COM port these days. If no additional COM Ports are listed, or equipped, you will need to install additional COM ports, either by, o o o
Installing a COM Port Expansion card in the PC – usually 2 port, more if possible. Obtaining an external USB to COM port converter device with 2 or more COM ports. Buy a Rig to Computer Interface package. See Decision, Point, Section 11.
9. Schematics
Schematics showing hardware interfaces follow, Figures 1 thru 5.
10. Requirements Summary
One COM port to be dedicated to the CI-V data function. A second COM port to be dedicated to the Accessory Control function. Recommend 2 more COM ports be equipped, ready to be assigned to other software applications. All Rig-PC Com connections need level converters, unless an interface product is employed. Must have Audio Isolating Transformers when connecting Tx and Rx audio to the Accessory socket. This will break ground loops that may otherwise induce hum or RF feedback.
11. Decision Point
You can buy complete interfaces that meet the above requirements as plug and play product. Some possibilities, http://www.westmountainradio.com/rigblaster.php http://microham-usa.com/store/product-info.php?pid6.html http://www.mfjenterprises.com/Product.php?productid=MFJ-1275
Do your own web search, or:
You can make your own per the supplied schematics. Attempt only if you are experienced in home construction. Have appropriate tools. Have a parts supplier.
Hope this helps.
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CONNECTING an ICOM RADIO to a PC
Figure 1 HARDWARE OVERVIEW of ICOM to PC CONNECTIVITY Icom IC-770
Desktop PC
Installed S/W Com 5
RS232 Serial Cable dB-9 Connectors
CI-V Level Converter
N1MM Logger +
CI-V Port
CW
Writelog V11.24
MMTTY V1.68A
Com 6
RS232 Serial Cable dB-9 Connectors
RS-232 Interface PTT-CW
Accessory
PTT
Audio Isolation Transformers
Line In
Pin 3 - SEND
Pin 4 – MOD Tx Audio
Line Out Sound Card
CW Key
Pin 5 – AF Rx Audio
FLDIGI V3.22.05
Com 3 RS232 Serial Cable dB-9 Connectors
RS-232 Interface FSK (for MMTTY)
1. COM Port numbers are arbitrary 2. All leads are sheilded 3. RS232 cables are 9 pin DB-9 style. All others are either RCA or 3.4 mm phono, monaural 4. Accessory socket is 8 pin DIN
4
FSK
Pin 1 - RTTY
CONNECTING an ICOM RADIO to a PC
Figure 2
CI -V / CT-17 Level Converter 78L05 5V Regulator 22u / 16V
+
1
+
MAX 232 +
1N4606
16
2
15
3
14
4
13
In
Out 22u / 16V
Gnd
BEAD
+ 4.7n
+12VDC
22u / 16V
4.7n
10u / 16V 2N2222
+
330R
BEAD
(white)
2k2
*FSK (TXD)
120pF
10u / 16V 5
12
6
11
1N4606
LED, Red
+
DB 9 RS-232
22u / 16V 7
10
8
9
GND
5
DTR
4
TXD
3
9
(blue) (violet)
8
RXD BEAD
CI-V (data)
120pF
BEAD
* PTT (DTR)
1N4606 (orange)
120pF
BEAD
CW (DTR)
DCD
1N4606 (green) 2k2
120pF 2N2222 1N4606
5
CTS
7
RTS
6
DSR
2
(grey) (yellow)
RI
1
CONNECTING an ICOM RADIO to a PC
Figure 3
COM PORT INTERFACE PTT / DTR
CW / RTS
FSK / TXD RTS
2N2222
Green
2k7
1N4606 120pF
CW (RTS)
Note 6
PTT (DTR)
Note 6
FSK (TXD)
Note 6
1N4606
2N2222
COM "N"
DTR
DB 9 RS-232 RI
DB 25 RTS = 4 DTR = 20 TXD = 2 GND = 5
CTS
Red
RTS DSR
9 8 7 6
1N4606 120pF 1N4606 GND
5 4 3
DTR TXD
Black Blue Brown
2N2222 TXD
White
2k7 1N4606
RXD
120pF
1N4606
2 1
Orange
2k7
DCD
Pin 1
1. Applications such as MMTTY, N1MM, WriteLog, Ham Radio Deluxe, and others commonly use the RTS, DTR,TXD lines of the RS-232 port to control Rig functions. 2. This Com Port to Rig Inferface converts the Computer RS-232 Com Port levels to "Open" and "Ground" levels which is commonly what the rig requires to operatethe PTT line, CW Key jack, and FSK line. 3. Not all applications use the same RS-232 line for the same rig function. Check each application for setup. 4. Note that all output circuits are the same. The only difference is the RS-232 pin that each interface is connected to. Therefore if an application must have DTR do CW keying, then the DTR interface circuit would be re-labeled as CW, not PTT. 5. More interface circuits can be added if, for instance, CTS is specified by an application as required for rig control, then reconnect one of the interface circuits to the CTS pin.
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CONNECTING an ICOM RADIO to a PC
Figure 4
ICOM ACCESSORY SOCKET WIRING
Accessory Interface Enclosure RCA
( TXD Com 4 ) RTTY- FSK
RCA
IC-7700 Accesory 1 Jack
(RTS) PTT
RCA
Squelch
6
7
13.8 VDC
1
8
3 RCA
4
5 2
3.5mm Stereo
Rx Audio
RG-174 Shield 3.5mm Stereo
Tx Audio
'Scope Vertical
RG-174
RCA
7
Ground
CONNECTING an ICOM RADIO to a PC
Figure 5
SOUND CARD ISOLATION TRANSFORMERS Metal Enclosure
3.5mm Stereo
600:600 Audio Xfmer
RCA
Tx Audio
Tx Audio
Line Out
PC Sound Card 3.5mm Stereo
600:600 Audio Xfmer
Rx Audio
To Radio Tx and Rx Audio RCA Rx Audio
Line In
Notes
1. The 3.5 mm Stereo jacks are grounded to metal enclosure. 2. The RCA jacks are completely isolated from metal enclosure. There must be no metallic connection between input and output circuits
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