Add GETHORIZTIMEBASE to gpib server

diff --git a/servers/gpib_server_lin/src/gpib_conn.cpp b/servers/gpib_server_lin/src/gpib_conn.cpp
index df5be78..74d787e 100644
--- a/servers/gpib_server_lin/src/gpib_conn.cpp
+++ b/servers/gpib_server_lin/src/gpib_conn.cpp
@@ -285,6 +285,18 @@
 										writeEndOfFrame();
 									}
 								}
+								else if (m_instrumentCommand == "GETHORIZTIMEBASE") {		// Want horizontal timebase
+									double timebase;
+									if (scope_get_timebase(&timebase, m_serverParent->m_scopeType.ascii(), m_serverParent->m_scopeDeviceSocket) == 0) {
+										ds << TQString("ACK");
+										ds << timebase;
+										writeEndOfFrame();
+									}
+									else {
+										ds << TQString("NCK");
+										writeEndOfFrame();
+									}
+								}
 								else if ((m_instrumentCommand == "GETCHANNELTRACE")) {		// Want channel trace
 									TQ_INT32 value;
 									ds >> value;
diff --git a/servers/gpib_server_lin/src/scope_functions.cpp b/servers/gpib_server_lin/src/scope_functions.cpp
index 5b3e34c..1e7c4ae 100644
--- a/servers/gpib_server_lin/src/scope_functions.cpp
+++ b/servers/gpib_server_lin/src/scope_functions.cpp
@@ -273,6 +273,55 @@
 	}
 }
 
+int scope_get_timebase(double * retval, const char * scopeType, int gpibDevice) {
+	char floatstring[1024];
+	long ai;
+	int max_num_bytes = 0;
+
+	if (strcmp("HP54600OS", scopeType) == 0) {
+		// FIXME
+		// Not supported (yet)
+		return -1;
+	}
+	else if (strcmp("TDS744AOS", scopeType) == 0) {
+		// Send request
+		printf("[INFO] Getting scope timebase\n\r");
+		sprintf(falpha,"HORIZONTAL:MAIN:SCALE?");
+		#ifdef ENABLE_EXTRA_DEBUGGING
+		printf("[DEBG] Writing: %s\n\r", falpha);
+		#endif
+		if (gpib_write(gpibDevice, falpha) == 0) {
+			max_num_bytes = 24;	// Request more bytes than are possible to ensure no bytes are left behind
+		}
+		else {
+			return 2;
+		}
+
+		// Read response
+		#ifdef ENABLE_EXTRA_DEBUGGING
+		printf("[DEBG] Trying to read %i bytes from GPIB device...\n", max_num_bytes);
+		#endif
+
+		ai = gpib_read_array(gpibDevice, max_num_bytes, floatstring);
+		if (ai == -1) {
+			return 1;
+		}
+		else {
+			floatstring[ai]=0;
+			*retval = atof(floatstring)*10;
+		}
+
+		#ifdef ENABLE_EXTRA_DEBUGGING
+		printf("[DEBG] Read %li bytes from GPIB device\n", ai);
+		#endif
+
+		return 0;
+	}
+	else {
+		return -1;
+	}
+}
+
 int scope_set_volts_div(int desired_channel, double desired_volts, const char * scopeType, int gpibDevice) {
 	if ((strcmp("HP54600OS", scopeType) == 0) || (strcmp("TDS744AOS", scopeType) == 0)) {
 		printf("[INFO] Setting scope volts/div on channel %d to %E\n\r", desired_channel, desired_volts);
diff --git a/servers/gpib_server_lin/src/scope_functions.h b/servers/gpib_server_lin/src/scope_functions.h
index ef33c64..1d8ee43 100644
--- a/servers/gpib_server_lin/src/scope_functions.h
+++ b/servers/gpib_server_lin/src/scope_functions.h
@@ -33,6 +33,7 @@
 int scope_get_screenshot_stage2(const char * scopeType, int gpibDevice);
 int scope_perform_initial_setup(const char * scopeType, int gpibDevice);
 int scope_set_timebase(float desired_timebase,const char * scopeType, int gpibDevice);
+int scope_get_timebase(double * retval, const char * scopeType, int gpibDevice);
 int scope_set_volts_div(int desired_channel, double desired_volts, const char * scopeType, int gpibDevice);
 int scope_set_acquisition(int status,const char * scopeType, int gpibDevice);
 int scope_get_acquisition(int * retval, const char * scopeType, int gpibDevice);