From b1dbadd93c04f3f346dbe709845f52c4435d4ba6 Mon Sep 17 00:00:00 2001
From: Adam Wujek <adam.wujek@cern.ch>
Date: Fri, 9 Jun 2017 17:06:36 +0200
Subject: [PATCH] userspace/tools: fix coefficient for link length calculations
Signed-off-by: Adam Wujek <adam.wujek@cern.ch>
---
userspace/tools/wr_mon.c | 28 ++++++++++++----------------
1 file changed, 12 insertions(+), 16 deletions(-)
diff --git a/userspace/tools/wr_mon.c b/userspace/tools/wr_mon.c
index 0a8cff13b..0bc4e42b5 100644
--- a/userspace/tools/wr_mon.c
+++ b/userspace/tools/wr_mon.c
@@ -590,14 +590,12 @@ void show_servo(int alive)
term_cprintf(C_BLUE, "Estimated link length: ");
/* (RTT - deltas) / 2 * c / ri
c = 299792458 - speed of light in m/s
- ri = 1.4682 - refractive index for fiber g.652 */
+ ri = 1.4682 - refractive index for fiber g.652. However,
+ experimental measurements using long (~5km) and
+ short (few m) fibers gave a value 1.4827
+ */
term_cprintf(C_WHITE, "%10.2f meters\n",
- (ppsi_servo_local.picos_mu
- - ppsi_servo_local.delta_tx_m
- - ppsi_servo_local.delta_rx_m
- - ppsi_servo_local.delta_tx_s
- - ppsi_servo_local.delta_tx_s
- ) / 2 / 1e6 * 299.792458 / 1.4682);
+ crtt / 2 / 1e6 * 299.792458 / 1.4827);
term_cprintf(C_BLUE, "Master-slave delay: ");
term_cprintf(C_WHITE, "%15.3f nsec\n",
@@ -670,16 +668,14 @@ void show_servo(int alive)
printf("dtxs:%d drxs:%d ", ppsi_servo_local.delta_tx_s,
ppsi_servo_local.delta_rx_s);
printf("asym:%lld ", total_asymmetry);
- /* Estimated link length in cm
- (RTT - deltas) / 2 * c / ri
+ /* (RTT - deltas) / 2 * c / ri
c = 299792458 - speed of light in m/s
- ri = 1.4682 - refractive index for fiber g.652 */
- printf("ll:%d ", (int) ((ppsi_servo_local.picos_mu
- - ppsi_servo_local.delta_tx_m
- - ppsi_servo_local.delta_rx_m
- - ppsi_servo_local.delta_tx_s
- - ppsi_servo_local.delta_tx_s
- ) / 2 / 1e6 * 299.792458 / 1.4682 * 100));
+ ri = 1.4682 - refractive index for fiber g.652. However,
+ experimental measurements using long (~5km) and
+ short (few m) fibers gave a value 1.4827
+ */
+ printf("ll:%d ",
+ (int) (crtt / 2 / 1e6 * 299.792458 / 1.4827 * 100));
printf("crtt:%llu ", crtt);
printf("cko:%lld ", ppsi_servo_local.offset);
printf("setp:%d ", ppsi_servo_local.cur_setpoint);
--
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