diff --git a/show/api_pos.php b/show/api_pos.php
index 19ff2c0..45ac017 100644
--- a/show/api_pos.php
+++ b/show/api_pos.php
@@ -48,6 +48,7 @@ function response_pos($api, $data) {
 	global $deviceInfo, $post, $log_id, $db;
 	$noncestr = md5(microtime().'_'.rand());
 	$time = time();
+	// 签名计算
 	$sign = md5($time.$noncestr.$deviceInfo['cardpwd']);
 	$data['sign'] = $sign;