Specifications

Configure a Synchronous Serial Interface
IC-76
Cisco IOS Interface Configuration Guide
Invert the Data
If the interface on the PA-8T and PA-4T+ synchronous serial port adapters is used to drive a
dedicated T1 line that does not have B8ZS encoding, you must invert the data stream on the
connecting CSU/DSU or on the interface. Be careful not to invert data on both the CSU/DSU and
the interface because two data inversions will cancel each other out.
If the T1 channel on the CT3IP is using AMI line coding, you must invert the data. For more
information, see the t1 linecode controller command. For more information on the CT3IP, refer to
the “Configure a Channelized T3 Interface Processor” section in this chapter.
To invert the data stream, use the following command in interface configuration mode:
Invert the Transmit Clock Signal
Systems that use long cables or cables that are not transmitting the TxC signal (transmit echoed
clock line, also known as TXCE or SCTE clock) can experience high error rates when operating at
the higher transmission speeds. For example, if the interface on the PA-8T and PA-4T+ synchronous
serial port adapters is reporting a high number of error packets, a phase shift might be the problem.
Inverting the clock signal can correct this shift. To invert the clock signal, use the following
command in interface configuration mode:
Set Transmit Delay
It is possible to send back-to-back data packets over serial interfaces faster than some hosts can
receive them. You can specify a minimum dead time after transmitting a packet to alleviate this
condition. This setting is available for serial interfaces on the MCI and SCI interface cards and for
the HSSI or MIP. Use one of the following commands, as appropriate for your system, in interface
configuration mode:
Command Purpose
invert data Invert the data on an interface.
Command Purpose
invert txclock Invert the clock signal on an interface.
invert rxclock
Inverts the phase of the RX clock on the UIO
serial interface, which does not use the T1/E1
interface.
Command Purpose
transmitter-delay microseconds Set the transmit delay on the MCI and SCI
synchronous serial interfaces.
transmitter-delay hdlc-flags Set the transmit delay on the HSSI or MIP.