COMCONTROL

Controls the serial port hardware control lines

Platform:

OEM719, OEM729, OEM7500, OEM7600, OEM7700, OEM7720

This command is typically used to control the hardware RTS control line of the serial communication (COM) ports; or, for SPAN applications, to output a 1PPS timing signal on a COM TX port. The TOGGLEPPS mode of this command is typically used to supply a timing signal to a host PC computer by using the RTS line. The PULSEPPSHIGH mode of this command is typically used to supply the timing pulse for SPAN applications by using the TX line. The accuracy of controlling the COM control signals is better than 900 µs. The other modes are typically used to control custom peripheral devices.

If handshaking is disabled, any of these modes can be used without affecting regular serial communications through the selected COM port. However, if handshaking is enabled, it may conflict with handshaking of the selected COM port, causing unexpected results. To use the COM2 flow control signals, COM5 must be disabled. See OEM7600, OEM7700 and OEM7720 Multiplexed Port for more information.

Message ID: 431

Abbreviated ASCII Syntax:

COMCONTROL [port] [signal] [control]

Factory Default:

COMCONTROL COM1 TX DEFAULT
COMCONTROL COM2 TX DEFAULT
COMCONTROL COM3 TX DEFAULT
COMCONTROL COM4 TX DEFAULT
COMCONTROL COM5 TX DEFAULT

ASCII Example 1:

INTERFACEMODE COM5 NONE NONE OFF (OEM7600, OEM7700 and OEM7720 only)
SERIALCONFIG COM2 9600 N 8 1 CTS (to enable handshaking)
COMCONTROL COM2 RTS FORCELOW

ASCII Example 2:

To set a break condition on COM1:

COMCONTROL COM1 TX FORCEHIGH

A break condition remains in effect until it is cleared. To clear a break condition on COM1:

COMCONTROL COM1 TX DEFAULT

or

COMCONTROL COM1 TX FORCELOW

Field	Field Type	ASCII Value	Binary Value	Description	Format	Binary Bytes	Binary Offset
1	Command header	-	-	COMCONTROL header This field contains the command name for abbreviated ASCII or the message header for ASCII (see page 1) or Binary (see page 1).	-	H	0
2	port	COM1	1	Serial port to control.	Enum	4	H
		COM2	2
		COM3	3
		COM4	19
		COM5	31
3	signal	RTS	0	COM signal to control. The controllable COM signals are RTS and TX.	Enum	4	H+4
		TX	2
4	control	See Table: Control Options		Control applied to the signal	Enum	4	H+8

Control Options

Binary	ASCII	Description
0	DEFAULT	Disables this command and returns the COM signal to its default state
1	FORCEHIGH	Immediately forces the signal high1 High on RS232; Low on UART
2	FORCELOW	Immediately forces the signal low2 Low on RS232; High on UART
3	TOGGLE	Immediately toggles the current state of the signal
4	TOGGLEPPS	Toggles the state of the selected signal within 900 μs after each 1PPS event. The state change of the signal lags the 1PPS by an average value of 450 μs. The delay of each pulse varies by a uniformly random amount less than 900 μs
5	PULSEPPSLOW	Pulses the line low at a 1PPS event and to high 1 ms after it.
6	PULSEPPSHIGH	Pulses the line high for 1 ms at the time of a 1PPS event

Port, Signal and Control Availability on OEM7 Receivers

	OEM719	OEM729	OEM7600	OEM7700	OEM7720
COM1 TX	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH
COM2 TX	N/A	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH
COM2 RTS	N/A	DEFAULT FORCEHIGH FORCELOW TOGGLE TOGGLEPPS PULSEPPSLOW PULSEPPSHIGH	DEFAULT FORCEHIGH FORCELOW TOGGLE TOGGLEPPS PULSEPPSLOW PULSEPPSHIGH	DEFAULT FORCEHIGH FORCELOW TOGGLE TOGGLEPPS PULSEPPSLOW PULSEPPSHIGH	DEFAULT FORCEHIGH FORCELOW TOGGLE TOGGLEPPS PULSEPPSLOW PULSEPPSHIGH
COM3 TX	N/A	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH
COM4 TX	N/A	N/A	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH
COM5 TX	N/A	N/A	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH	DEFAULT FORCEHIGH FORCELOW PULSEPPSHIGH