每秒脉冲 - PPS

在启用 PPS 输入之前，请确保在交换机上配置 PTP 从端口。请参阅精确时间协议 - PTP。

cumulus@switch:~$ nv set platform pulse-per-second in state enabled
cumulus@switch:~$ nv config apply

cumulus@switch:~$ nv set platform pulse-per-second out state enabled
cumulus@switch:~$ nv config apply

1. 编辑 `/etc/ptp4l.conf` 文件的 `Default interface options` 部分，以在交换机上配置 PTP 从端口。PPS 输入需要 PTP 从端口。有关 PTP 的信息，请参阅精确时间协议 - PTP。

   cumulus@switch:~$ sudo nano /etc/linuxptp/pps_out.conf
   ...
   # Default interface options
   #
   time_stamping                  hardware
   [swp29]
   udp_ttl                      1
   masterOnly                   0
   delay_mechanism              E2E
   network_transport            RAWUDPv4
   

2. 编辑 `/etc/linuxptp/ts2phc.conf` 文件以设置以下参数来启用 PPS 输入。

   cumulus@switch:~$ sudo nano /etc/linuxptp/ts2phc.conf
   # Default configurations
   [global]
   use_syslog                0
   verbose                   1
   logging_level             6
   slave_event_monitor       /var/run/ptp_sem.sock
   ts2phc.pulsewidth         500000000
   ts2phc.tod_source         ptp 
   #
   # servo parameters
   #
   pi_proportional_const          0.000000
   pi_integral_const              0.000000
   pi_proportional_scale          0.700000
   pi_proportional_exponent       -0.300000
   pi_proportional_norm_max       0.700000
   pi_integral_scale              0.300000
   pi_integral_exponent           0.400000
   pi_integral_norm_max           0.300000
   step_threshold                 0.000000050
   first_step_threshold           0.000000001
   max_frequency                  500000000
   sanity_freq_limit              0
   #
   [/dev/ptp1] 
   ts2phc.pin_index               0 
   ts2phc.channel                 0
   ts2phc.extts_polarity          rising 
   ts2phc.extts_correction        0
   

3. 启用并启动 `ptp4l` 和 `phc2sys` 服务

   cumulus@switch:~$ sudo systemctl enable ptp4l.service phc2sys.service
   cumulus@switch:~$ sudo systemctl start ptp4l.service phc2sys.service
   

1. 编辑 `/etc/linuxptp/pps_out.conf` 文件以设置以下参数。

   cumulus@switch:~$ sudo nano /etc/linuxptp/pps_out.conf
   # Configuration file used for the pps_out.service
   # It is shell formatted and the file is source'd by the service
   # Set the PTP device to source our PPS from. 
   # If not specified, the service will find the first device with a clock name "sx_ptp".
   PTP_DEV=/dev/ptp1
   # Set the pin index on the PPS device to send on. 
   # On the NVIDIA systems, only pin 1 (0-based) is supported
   OUT_PIN=1
   # Set the file where to cache the last started values. 
   # This is used primarily in the "stop" operation to know what to clean up.
   CACHE_FILE=/var/run/pps_out
   # Set the out pulse charateristics for frequency and width
   PULSE_FREQ=1000000000
   PULSE_WIDTH=500000000
   PULSE_PHASE=0
   

2. 启用并启动 `pps_out` 服务

   cumulus@switch:~$ sudo systemctl enable pps_out.service 
   cumulus@switch:~$ sudo systemctl start pps_out.service 
   

以下示例配置 PPS 输入并设置

• 通道索引为 1。
• 引脚索引为 1。
• 信号宽度为 999000000。
• 时间戳校正为 1000000000。
• 日志记录级别为 warning。
• PPS 输入信号的极性为 `falling-edge`。

cumulus@switch:~$ nv set platform pulse-per-second in channel-index 1
cumulus@switch:~$ nv set platform pulse-per-second in pin-index 1
cumulus@switch:~$ nv set platform pulse-per-second in signal-width 999000000
cumulus@switch:~$ nv set platform pulse-per-second in timestamp-correction 1000000000
cumulus@switch:~$ nv set platform pulse-per-second in logging-level warning
cumulus@switch:~$ nv set platform pulse-per-second in signal-polarity falling-edge
cumulus@switch:~$ nv config apply

以下示例配置 PPS 输出并设置

• 通道索引为 1。
• 信号宽度为 999000000。
• PPS 输出信号的频率调整为 2147483647。

cumulus@switch:~$ nv set platform pulse-per-second out channel-index 1
cumulus@switch:~$ nv set platform pulse-per-second out signal-width 999000000
cumulus@switch:~$ nv set platform pulse-per-second out frequency-adjustment 2147483647
cumulus@switch:~$ nv config apply

要配置 PPS 输入，请编辑 `/etc/linuxptp/ts2phc.conf` 文件，然后使用 `sudo systemctl restart ts2phc.service` 命令重启 PPS 输入服务。

以下示例配置 PPS 输入并设置

• 通道索引为 1
• 引脚索引为 1
• 信号宽度为 999000000。
• 时间戳校正为 1000000000。
• 日志记录级别为 4（警告）。
• PPS 输入信号的极性为下降沿 (`falling`)。

cumulus@switch:~$ sudo nano /etc/linuxptp/ts2phc.conf
# ts2phc is enabled 
[global] 
use_syslog                     0 
verbose                        1 
slave_event_monitor            /var/run/ptp_sem.sock 
logging_level                  4 
ts2phc.pulsewidth              999000000 
ts2phc.tod_source              ptp 
domainNumber                   0
...
[/dev/ptp1] 
ts2phc.pin_index               1 
ts2phc.channel                 1 
ts2phc.extts_polarity          falling 
ts2phc.extts_correction        0

要配置 PPS 输出，请编辑 `/etc/linuxptp/pps_out.conf.conf` 文件，然后使用 `sudo systemctl restart pps_out.service` 命令重启 PPS 输出服务。

以下示例配置 PPS 输出并设置

• 通道索引为 1。
• 信号宽度为 999000000。
• PPS 输出信号的频率调整为 2147483647。

cumulus@switch:~$ sudo nano /etc/linuxptp/pps_out.conf.conf
# Configuration file used for the pps_out.service
# It is shell formatted and the file is source'd by the service
#
# Set the PTP device to source our PPS from. 
# If not specified, the service will find the first device with a clock name "sx_ptp".
PTP_DEV=/dev/ptp1
#
# Set the pin index on the PPS device to send on. 
# On the NVIDIA systems, only pin 1 (0-based) is supported
OUT_PIN=1
#
OUT_CHANNEL=1 
#
# Set the file where to cache the last started values. 
# This is used primarily in the "stop" operation to know what to clean up.
CACHE_FILE=/var/run/pps_out
#
# Set the out pulse charateristics for frequency and width
PULSE_FREQ=2147483647
PULSE_WIDTH=999000000
PULSE_PHASE=1000000000