Configuring VMI Telephony Properties

If your Vocera installation includes Vocera SIP Telephony Gateway for telephony integration, you can configure trunk access codes (or TACs) to specify how specific dial strings are processed to define how a Vocera badge interacts with telephony equipment via a VMI client application.

These properties are designed for use with VMI applications in the following situations:

The collection of VMI telephony properties must be complete. If you comment out one property in the collection, you must comment out the entire collection. You can, however, specify one or more empty values for a property in this collection. By default, the VMI telephony properties are undefined and therefore disabled. The following table describes these properties.
Table 1. VMI telephony properties
Property Description

TelVMIDeviceTAC

Specifies a trunk access code (TAC) to identify a device (such as a nurse call system) that connects to a PBX to communicate with a Vocera badge. By default, this property value is not defined. When it is defined, this value activates the gain specified by the corresponding TelVMIRxGain property, and the macro defined by the corresponding TelVMIHangUpMacro property.

The TAC for any given device is set by the PBX administrator. To specify TACs for multiple devices, use a forward slash (/) as a separator character. White space is ignored. You can specify up to 50 TACs.

If two or more TACs begin with the same sequence of characters, list them in descending order of length. For example, each of the following TACs begins with the sequence 12: 12, 123, and 12345. In the properties file, you would list them in the following order:

12345   /   123   /   12

TelVMIRxGain

Specifies how much gain is added when a badge user chooses the callback option to respond to a VMI message. By increasing or decreasing this value, you increase or decrease the sound level (volume) of the badge speaker in 6 dB increments.

For example, a value of 3 increases the volume by 18 dB (3 * 6 = 18). Valid values range from 0 to 6, inclusive. By default, this property value is not defined. Optimum values should be determined in the field by trial and error.

The specified gain is applied only if the corresponding TelVMIDeviceTAC property is defined. The gain is removed when the call ends. To specify gains for multiple devices, use the forward slash (/) as a separator character. White space is ignored. You can specify up to 50 gain values.

TelVMIHangUpMacro

Specifies a sequence to dial when a Vocera badge ends a call initiated using the callback option in response to a VMI message. This property is especially useful when interacting with a device that connects to a PBX via an analog line.

The required sequence varies depending on the device. For example, nurse call systems from different vendors require different hang-up sequences. Consult the device documentation for details.

The specified sequence is dialed only if the corresponding TelVMIDeviceTAC property is defined. To specify more than one macro, use the forward slash (/) as a separator character. White space is ignored. You can specify up to 50 macros.

When you specify more than one value for any of these properties, the order is important:

For example, suppose a VMI client application interacts with a nurse call system made by company NC1, a blood pressure monitoring system made by company BP, and another nurse call system made by company NC2. The following code lists some sample values for this scenario:

#                    NC1   BP    NC2
#------------------------------------
TelVMIDeviceTAC   = 835 / 7812 / 781
TelVMIRxGain      =  4  /      / 2
TelVMIHangUpMacro = ##  /      / *9*

In this example, a gain value of 4 and the hang-up macro ## are defined for nurse call system NC1, which has the TAC 835. Similarly, a gain value of 2 and the hang-up macro *9* are defined for nurse call system NC2, which has the TAC 781. However, the blood pressure monitor BP, which has the TAC 7812, does not define a gain value or a hang-up macro. In the properties file, such "empty" values can either be omitted or specified explicitly with spaces. Also, the TAC for BP is listed before the TAC for NC2 because both TACs begin with the sequence 781 and the TAC for BP is longer than the TAC for NC2. Listing the TACs in this order ensures that the Vocera parser will extract them correctly from a dial string.